I have the c code for the micro-controller with buzzer. It works, but I wonder how it works.
In wh.h/.cpp I have the function:
void setBuzzer(tBool on)
{
if (TRUE == on)
IOCLR = BUZZER_PIN;
else
IOSET = BUZZER_PIN;
}
That can enable and disable the buzzer. I don't know what it really makes and what BUZZER_PIN, IOCLR and IOSET are?
The BUZZER_PIN occurs only once more in the code, in:
void immediateIoInit(void)
{
tU8 initCommand[] = {0x12, 0x97, 0x80, 0x00, 0x40, 0x00, 0x14, 0x00, 0x00};
// 04 = LCD_RST# low
// 10 = BT_RST# low
//make all key signals as inputs
IODIR &= ~(KEYPIN_CENTER | KEYPIN_UP | KEYPIN_DOWN | KEYPIN_LEFT | KEYPIN_RIGHT);
IODIR |= BUZZER_PIN;
IOSET = BUZZER_PIN;
IODIR |= BACKLIGHT_PIN;
IOSET = BACKLIGHT_PIN;
It looks strange to me, because the IOSET value is changing just after setting it to BUZZER_PIN. So, what it can that way does?
One more question: can I do something more with buzzer? E.g. change to volume? Of course, the duration of sound can be adjusted with setBuzzer(1) than pause(time) and setBuzzer(0).
Somewhere you will find an include file that contains the #define for IOSET IOCLR etc.
Usually, they map to GPIO register addresses, eg:
#define FIO0DIR (*(volatile unsigned long *)0x3FFFC000)
IOSET is usually a writeable address that is hardware-capable of setting to 1 all bits written to it that are 1, while leaving the remainder of the GPIO bits in their previous state. This eliminates the need for a read/modify/write operation and so is much more interrupt/thread friendly. It normally has a similar 'IOCLR' partner that can clear the bits on the GPIO port that are set in its argument without affecting the state of others.
The port register itself is probabaly called' IOPIN', or something like that. Modifying one or subsets of bits directly using IOPIN requires a read/modify/write :(
It appears that the buzzer is connected to one GPIO pin, so you can only turn it on and off - no finer control is possible.
Related
I am using the STM32F0 using register level coding and am having problems with the CRC module.
Basically I cant get the results to agree with online calculators.
I've stripped it right back to as simple as possible.
If I just reset the CRC then read the Data Register out I get 0xFFFFFFFF which I would expect as that's the initial value.
Even if I write zero in though and get the result it does not agree with other tools.
The STM outputs 0xC704DD7B and the online tools give 0xF4DBDF21.
As far as I can see all the parameters are the same (I have not tried to hand calculate it!).
My bare bones code is (and I am reading the result in the debugger from the register)...
// Reset the CRC.
SET_BIT(CRC->CR, CRC_CR_RESET_Pos);
// Write 0.
CRC->DR, 0;
I am not really sure, but maybe this helps:
I once had the same problem and i tried to figure out how to get the "correct" CRC32. Unfortunately there is not "one" type how CRC32 could be calculated, but several of ways. See https://crccalc.com/
I allways leave the settings of the CRC peripheral on default:
Default Polynomial state -> Enable
Default Init Value State -> Enable
Enable Input Data Inversion Mode -> None
None Output Data Inversion Mode -> Disable
Except "Input Data Format", which I set to "Words".
When sending data to the peripheral, I revert the words "word-wise". The Result is reverted word-wise again. This leads to an CRC32 which can be verified as CRC32/MGPE2
I have a function, that tests, if If I have configured the CRC Peripheral correctly, so I get "the correct" CRC32/MPEG2:
uint8_t CRC32Test(void) {
// #brief test if CRC32 Module is configured correctly
// #params none, void
// #return u8 status: 1 = OK, 0 = NOK (not configured correctly)
// Test if CRC Module is configured correctly.
// If YES, these data must return the CRC32 0x07 D4 12 72 (Big Endian)
// or - 0x72 12 d4 07 (little Endian)
uint8_t retval = 0;
uint8_t testdata[] = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x00, 0x00};
uint32_t CRCdataU32[3] = {0,};
uint32_t* pCRCdata = (uint32_t*)testdata;
uint32_t dataSz = 3;
CRCdataU32[0] = __REV(*pCRCdata++);
CRCdataU32[1] = __REV(*pCRCdata++);
CRCdataU32[2] = __REV(*pCRCdata++);
uint32_t testCRC32 = HAL_CRC_Calculate(&hcrc, CRCdataU32, dataSz);
testCRC32 = __REV(testCRC32);
if(testCRC32 == 0x7212d407) retval = 1;
return(retval);
}
I verified this, using crccalc.com
This is most probably not the most elegant code, but it works for me. I use it for data transfer between the MCU and a PC over RS232/RS485. I don't care much which special CRC32 I use. I just need both to create the same results on the receiver and the sender. And I archieve that with that code.
I am trying to test the i2c communication of the MAX77651 chip before programming it.
So here is my setup to do so:
I have an UMFT4222ev connected to my Linux laptop by USB. This chip has his SCL and SDA linked to the SDA and SCL of my MAX77651 thanks to the Evaluation Kit for the MAX77651. My MAX77651evkit is powered with 3,7V on the Vbatt pin.
I also installed the mraa librarie from git hub and the libft4222. I know mraa is well installed because i tried it with and example.
I was told that the mraa library takes in charge the setup of the FT4222 so i only used mraa functions to make my program.
I searched on the website of Maxim integrated the i2c slave address and one register where i could read data and check if everyting is working. I then read the i2c protocol of communication to read a single register which is available here : https://datasheets.maximintegrated.com/en/ds/MAX77650-MAX77651.pdf at the page 78.
With all those informations I tried to make my "test program". I solved the compiling errors but when I execute the program I can't get what is in the register which should be 0xFF.
Here is my program:
#include "stdio.h"
#include "syslog.h"
#include "string.h"
#include "unistd.h"
#include "mraa/i2c.h"
#include "mraa.h"
#define I2C_ADDR 0x48
int
main(int argc, char *argv[])
{
uint8_t *message;
*message=0XAC;
int i,j,k;
char reg_a_lire = 0x06;
mraa_init();
mraa_i2c_context i2c;
i2c = mraa_i2c_init(0);
mraa_i2c_frequency(i2c,MRAA_I2C_FAST);
mraa_i2c_address(i2c, I2C_ADDR);
mraa_i2c_write_byte(i2c,0x90);
mraa_i2c_read(i2c, message,1);
mraa_i2c_write_byte(i2c,reg_a_lire);
mraa_init();
mraa_i2c_write_byte(i2c,0x91);
mraa_i2c_read(i2c, message,1);
mraa_i2c_read(i2c, message,1);
printf("%02X \n", *message);
mraa_i2c_stop(i2c);
return 0;
}
Here is the actual output :
alex#cyclonit-laptop ~/Test_alex/tests $ ./a.out
AC
And i would like to get FF instead of AC.
I think my error could come from something i missed to initialize the FT4222 or from the MAX77651 which I maybe did nt power up correctly and its not sufficient to put 3,7V on Vbatt. But maybe this is a problem with my program because i don't know much about uint8_t and I made something wrong.
I am hoping someone has experience with FT4222 and/or MAX77651 and can help me.
I think you are confused by pg. 75 of the MAX77651 datasheet.
ADDRESS | 7-BIT SLAVE ADDRESS | 8-BIT WRITE ADDRESS | 8-BIT READ ADDRESS
Main Address | 0x48, 0b 100 1000 | 0x90, 0b 1001 0000 | 0x91, 0b 1001 0001
(ADDR = 1)* | | |
-------------+---------------------+---------------------+-------------------
Main Address | 0x40, 0b 100 0000 | 0x80, 0b 1000 0000 | 0x81, 0b 1000 0001
(ADDR = 0)* | | |
Depending on your view of the I²C specification, you either use the 7-bit address or use both 8-bit addresses. The reason is that the first I²C transaction sends the following 8 bit:
76543210
\_____/\-- R/#W
\------ 7-bit Slave Address
In your case that's 0x48 shifted one bit to the left followed by either a 1 for read mode or a 0 for write mode. Notice that
(0x40 << 1) | 0x00 == 0x80 == 8-bit Write Address (ADDR = 0)
(0x40 << 1) | 0x01 == 0x81 == 8-bit Read Address (ADDR = 0)
(0x48 << 1) | 0x00 == 0x90 == 8-bit Write Address (ADDR = 1)
(0x48 << 1) | 0x01 == 0x91 == 8-bit Read Address (ADDR = 1)
Some people like to use the slave address while other people prefer to give separate addresses so it's clear what the first byte of communication will look like.
So you should remove the extraneous mraa_i2c_write_byte(i2c, ...); lines from your code, as their intention seems to be to send the read or write address to the slave.
Check out the MRAA library API reference. There are functions that abstract reading and writing registers, either byte-wide [8-bit] registers or word-wide [16-bit] registers:
mraa_i2c_read_byte_data
mraa_i2c_read_bytes_data
mraa_i2c_write_byte_data
In both cases you should check the return codes to know if the action succeeded. In your case, your message is likely not altered, because there was a stop/error condition beforehand, because the slave did either not ACK its slave address or it did not ACK the 0x90/0x91 data bytes you mistakenly sent, as they don't show up in the Programmer's Guide as valid addresses.
Another issue is that you try to read register INTM_GLBL (0x06; Global Interrupt Mask Register) using two consecutive read operations. I'm not sure if your intention is to read register 0x06 twice or if you intended to read INT_M_CHG (0x07; Global Interrupt Mask for Charger), because that's not what it will do. Notice the description on pg. 78 of the datasheet:
Note that when the MAX77650/MAX77651 receive a stop
they do not modify their register pointer.
This is typical behavior for I²C slaves that support multi-byte/sequential reads. You will have to issue a sequential read operation for multiple bytes of data if you want to read multiple registers, e.g. using mraa_i2c_read_bytes_data.
Something like the following might get you on the right track. It is supposed to read the CID and CLKS settings and wait forever if a read error occurred. If successful, it will disable charging, all outputs, setup the red LED to blink once every other second and -- as soon as you uncomment it -- transition the On/Off Controller into On Via Software state to enable bias and the LED.
#define MAX77651_SLA 0x48u
#define CNFG_GLBL_REG 0x10u
#define CID_REG 0x11u
#define CNFG_CHG_B_REG 0x19u
#define CNFG_SBB0_B_REG 0x2Au
#define CNFG_SBB1_B_REG 0x2Cu
#define CNFG_SBB2_B_REG 0x2Eu
#define CNFG_LDO_B_REG 0x39u
#define CNFG_LED1_A_REG 0x41u
#define CNFG_LED1_B_REG 0x44u
#define CNFG_LED_TOP_REG 0x46u
int main(int argc, char *argv[]) {
uint8_t data;
int res;
mraa_init();
mraa_i2c_context i2c0;
i2c0 = mraa_i2c_init(0);
mraa_i2c_frequency(i2c0, MRAA_I2C_STD);
mraa_i2c_address(i2c0, MAX77651_SLA);
res = mraa_i2c_read_byte_data(i2c0, CID_REG);
if (res < 0) {
printf("Reading CID_REG failed.\n");
mraa_i2c_stop(i2c0);
while(1);
}
data = res;
printf("CID_REG: CLKS = %02X CID = %02X\n", ((data & 0x70u) >> 4), (data & 0x0Fu));
/* you should check return values here */
mraa_i2c_write_byte_data(i2c0, 0x00u /* CHG_EN = off */, CNFG_CHG_B_REG);
mraa_i2c_write_byte_data(i2c0, 0x04u /* EN_LDO = off */, CNFG_LDO_B_REG);
mraa_i2c_write_byte_data(i2c0, 0x04u /* EN_SBB0 = off */, CNFG_SBB0_B_REG);
mraa_i2c_write_byte_data(i2c0, 0x04u /* EN_SBB1 = off */, CNFG_SBB1_B_REG);
mraa_i2c_write_byte_data(i2c0, 0x04u /* EN_SBB2 = off */, CNFG_SBB2_B_REG);
/* set up red led to toggle every second */
mraa_i2c_write_byte_data(i2c0, 0x17u /* P = 1s, D = 50% */, CNFG_LED1_B_REG);
mraa_i2c_write_byte_data(i2c0, 0x98u /* FS = 6.4mA, BRT = 5.0mA */, CNFG_LED1_A_REG);
mraa_i2c_write_byte_data(i2c0, 0x01u /* EN_LED_MSTR = on */, CNFG_LED_TOP_REG);
// DANGER ZONE: enable only when you know what this is supposed to do
//mraa_i2c_write_byte_data(i2c0, 0x10u /* SBIA_EN = on, SBIA_LPM = normal */, CNFG_GLBL_REG);
mraa_i2c_stop(i2c0);
while(1);
}
I managed to read I2C registers of MAX77651.
First looking at the hardware part I had to make sure that VIO had the right voltage like #FRob said in hid comment.
Then for the software, I stopped using the mraa library because i could'nt control everything. I used the FT4222 library which allowed me to open and initiate the FT4222 device. I took some part of the I2C example in this library for the initialization of the device. Then I noticed that I had to first use the FT4222's write function to send the register i wanted to read , then simply use the read function to get my result. Those are the two steps required.
I won't post the whole program i made as it is mainly taken from the I2C example for initialization but here is the part I added to read my register 0X06 which is supposed to contain 0xFF:
uint8 resultat=0x11;
uint8 *p_resultat=&resultat;
int chiffre;
slaveAddr
uint16 bytesToWrite2 = 1;
uint16 bytesWritten2=1;
uint8 valeur= 0x06; // REGISTER TO READ
uint8 *p_valeur=&valeur;
FT4222_I2CMaster_Write(ftHandle,slaveAddr,
p_valeur,bytesToWrite2,&bytesWritten); //INDICATES WHICH REGISTER TO
// READ
chiffre = FT4222_I2CMaster_Read(ftHandle,
slaveAddr,p_resultat,1, &bytesRead); // READ REGISTER
printf("The content of the register %02X is : %02X \n " ,
valeur,resultat); // DISPLAY RESULT
printf("reading success if : %d = 0 \n " , chiffre);
// READING SUCCESS ?
With this code and the initialization i get the following result :
alex#cyclonit-laptop ~/Downloads/libft4222-1.2.1.4/examples $ ./a.out
Device 0 is interface A of mode-0 FT4222H:
0x0403601c FT4222 A
Chip version: 42220200, LibFT4222 version: 01020104
The content of the register 06 is : FF
reading success if : 0 = 0
Skipping interface B of mode-0 FT4222H.
If someone has the same problem you are free to ask me your question by answering this post.I am very thankful to the people here who helped me!
I am working on a Motorola HCS08 µCU in CodeWarrior V10.6, I am trying to create an extern bitfield which has bits from existing registers. The way the bitfields are created in the µCU header is like
typedef unsigned char byte;
typedef union {
byte Byte;
struct {
byte PTAD0 :1;
byte PTAD1 :1;
byte PTAD2 :1;
byte PTAD3 :1;
byte PTAD4 :1;
byte PTAD5 :1;
byte PTAD6 :1;
byte PTAD7 :1;
} Bits;
} PTADSTR;
extern volatile PTADSTR _PTAD #0x00000000;
#define PTAD _PTAD.Byte
#define PTAD_PTAD0 _PTAD.Bits.PTAD0
#define PTAD_PTAD1 _PTAD.Bits.PTAD1
#define PTAD_PTAD2 _PTAD.Bits.PTAD2
#define PTAD_PTAD3 _PTAD.Bits.PTAD3
#define PTAD_PTAD4 _PTAD.Bits.PTAD4
#define PTAD_PTAD5 _PTAD.Bits.PTAD5
#define PTAD_PTAD6 _PTAD.Bits.PTAD6
#define PTAD_PTAD7 _PTAD.Bits.PTAD7
Which will let the register value be changed either by PTAD = 0x01, or PTAD_PTAD0 = 1, for example. This definition is basically the same for PTAD, PTBD, PTCD, ... PTGD, the only thing changing is the address.
My attemp to create a custom bitfield out of the previous existing variables is
typedef union {
byte Byte;
struct {
byte *DB0;
byte *DB1;
byte *DB2;
byte *DB3;
byte *DB4;
byte *DB5;
byte *DB6;
byte *DB7;
} Bits;
} LCDDSTR;
I would create and initialize the bitfield as LCDDSTR lcd = {{&PTGD_PTGD6, &PTBD_PTBD5, ...}}, because by some reason, the initialization like LCDSTR lcd = {*.Bits.DB0 = &PTGD_PTGD6, *.Bits.DB1 = &PTBD_PTBD5, ...} (treating it as a struct, please correct me again) advice in How to initialize a struct in accordance with C programming language standards does not work with this compiler (it does work on an online compiler).
However, as you may see I am sort of grouping the bits, and (if it would work) I would be able to change the values of the actual register by doing *lcd.Bits.DB0 = 1, or something like that, but if I do lcd.Byte = 0x00, I would be changing the last (I think) byte of the memory address contained in lcd.Bits.DB0, you know, because the struct doesn't actually contains the data, but the pointers instead.
How would I go on achieving a struct that is able to contain and modify bits from several registers? (I guess the problem here is that in memory the bits are not one next to the other, which I guess would make it easier). Is it even possible? I hope it is.
How would I go on achieving a struct that is able to contain and modify bits from several registers? (I guess the problem here is that in memory the bits are not one next to the other..
I don't think you can do it with a struct. That is because bitfields by definition have to occupy the same or contiguous addresses.
However macros may be useful here
#define DB0 PTGD_PTGD6
#define DB1 PTBD_PTBD5
....
And to clear the bits to all 0's or set to all 1's you can use a multiline macro
#define SET_DB(x) do { \
PTGD_PTGD6 = x; \
PTBD_PTBD5 = x; \
...... \
} while(0)
How would I go on achieving a struct that is able to contain and modify bits from several registers?
You can't.
A structure must represent a single, continuous block of memory -- otherwise, operations like taking the sizeof the structure, or performing operations on a pointer to one would make no sense.
If you want to permute the bits of a value, you will need to find some way of doing so explicitly. If the order of your bits is relatively simple, this may be possible with a few bitwise operations; if it's weirder, you may need to use a lookup table.
Beyond that: bitfields in C are pretty limited. The language does not make a lot of guarantees about how a structure containing bitfields will end up laid out in memory; they are generally best avoided for portable code. (Which doesn't apply here, as you're writing code for a specific compiler/microcontroller combination, but it's worth keeping in mind in general.)
Your union does unfortunately not make any sense, because it forms a union of one byte and 8 byte*. Since a pointer is 16 bit on HCS08, this ends up as 8*2 = 16 bytes of data, which can't be used in any meaningful way.
Please note that the C structure called bit-fields is very poorly specified by the standard and therefore should be avoided in any program. See this.
Please note that the Codewarrior register maps aren't remotely close to following the C standard (nor MISRA-C).
Please note that structs in general are problematic for hardware register mapping, since structs can contain padding. You don't have that problem on HCS08 specifically, since it doesn't require alignment of data. But most MCUs do require that.
It is therefore better to roll out your own register map in standard C if you have that option. The port A data register could simply be defined like this:
#define PTAD (*(volatile uint8_t*)0x0000U)
#define PTAD7 (1U << 7)
#define PTAD6 (1U << 6)
#define PTAD5 (1U << 5)
#define PTAD4 (1U << 4)
#define PTAD3 (1U << 3)
#define PTAD2 (1U << 2)
#define PTAD1 (1U << 1)
#define PTAD0 (1U << 0)
As we can tell, defining the bit masks is mostly superfluous anyway, as PTAD |= 1 << 7; is equally readable to PTAD |= PTAD7;. This is because this was a pure I/O port. Defining textual bit masks for status and control registers on the other hand, increases the readability of the code significantly.
If you want to modify bits from several registers, you'd do something like the following:
Assume we have a RGB (red-green-blue) LED, common cathode, with 3 colors connected to 3 different pins on 3 different ports. Instead of beating up the PCB designer, you could do this:
#define RGB_RED_PTD PTAD
#define RGB_RED_PTDD PTADD
...
#define RGB_BLUE_PTD PTBD
#define RGB_BLUE_PTDD PTBDD
...
#define RGB_GREEN_PTD PTDD
#define RGB_GREEN PTDD PTDDD
#define RGB_RED_PIN 1
#define RGB_BLUE_PIN 5
#define RGB_GREEN_PIN 3
You can now set these independently of where they happen to be located on the hardware:
void rgb_init (void)
{
RGB_RED_PTDD |= (1 << RGB_RED_PIN);
RGB_BLUE_PTDD |= (1 << RGB_BLUE_PIN);
RGB_GREEN_PTDD |= (1 << RGB_GREEN_PIN);
}
void rgb_yellow (void)
{
RGB_RED_PTD |= (1 << RGB_RED_PIN);
RGB_BLUE_PTD &= ~(1 << RGB_BLUE_PIN);
RGB_GREEN_PTD |= (1 << RGB_GREEN_PIN);
}
And so on. Examples were for HCS08 but the same can of course be used universally on any MCU with direct port I/O.
It sounds like an approach such as the following is along the lines of where you would like to go with a solution.
I have not tested this as I do not have the hardware however this should provide an alternative to look at.
This assumes that you want to turn on particular pins or turn off particular pins but there will not be a case where you will want to turn on some pins and turn off other pins for a particular device in a single operation. If that should be the case I would consider making the type of RegPinNo be an unsigned short to include an op code for each register/pin number combination.
This also assumes that timing of operations is not a critical constraint and that the hardware has sufficient horsepower such that small loops are not much of a burden on throughput and hogging CPU time needed for other things. So this code may need changes to improve optimization if that is a consideration.
I assume that you want some kind of a easily readable way of expressing a command that will turn on and off a series of bits scattered across several areas of memory.
The first thing is to come up with a representation of what such a command would look like and it seems to me that borrowing from a char array to represent a string would suffice.
typedef byte RegPinNo; // upper nibble indicates register number 0 - 7, lower nibble indicates pin number 0 - 7
const byte REGPINNOEOS = 0xff; // the end of string for a RegPinNo array.
And these would be used to define an array of register/pin numbers as in the following.
RegPinNo myLed[] = { 0x01, 0x12, REGPINNOEOS }; // LED is addressed through Register 0, Pin 0 and Register 1, Pin 1 (zero based)
So at this point we have a way to describe that a particular device, an LED in this case, is addressed through a series of register/pin number items.
Next lets create a small library of functions that will use this representation to actually modify the specific pins in specific registers by traversing this array of register/pin numbers and performing an operation on it such as setting the bit in the register or clearing the bit in the register.
typedef unsigned char byte;
typedef union {
byte Byte;
struct {
byte PTAD0 : 1;
byte PTAD1 : 1;
byte PTAD2 : 1;
byte PTAD3 : 1;
byte PTAD4 : 1;
byte PTAD5 : 1;
byte PTAD6 : 1;
byte PTAD7 : 1;
} Bits;
} PTADSTR;
// Define a pointer to the beginning of the register area. This area is composed of
// 8 different registers each of which is one byte in size.
// We will address these registers as Register 0, Register 1, ... Register 7 which just happens
// to be how C does its zero based indexing.
// The bits representing pins on the PCB we will address as Pin 0, Pin 1, ... Pin 7.
extern volatile PTADSTR (* const _PTAD) = 0x00000000;
void SetRegPins(RegPinNo *x)
{
byte pins[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
int i;
for (i = 0; x[i] != REGPINNOEOS; i++) {
byte bRegNo = (x[i] >> 4) & 0x07; // get the register number, 0 - 7
byte bPinNo = x[i] & 0x07; // get the pin number, 0 - 7
_PTAD[bRegNo].Byte |= pins[bPinNo];
}
}
void ClearRegPins(RegPinNo *x)
{
byte pins[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
int i;
for (i = 0; x[i] != REGPINNOEOS; i++) {
byte bRegNo = (x[i] >> 4) & 0x07; // get the register number, 0 - 7
byte bPinNo = x[i] & 0x07; // get the pin number, 0 - 7
_PTAD[bRegNo].Byte &= ~pins[bPinNo];
}
}
void ToggleRegPins(RegPinNo *x)
{
byte pins[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
int i;
for (i = 0; x[i] != REGPINNOEOS; i++) {
byte bRegNo = (x[i] >> 4) & 0x07; // get the register number, 0 - 7
byte bPinNo = x[i] & 0x07; // get the pin number, 0 - 7
_PTAD[bRegNo].Byte ^= pins[bPinNo];
}
}
You would use the above something like the following. Not sure what a time delay function would look like in your environment so I am using a function Sleep() which takes an argument as to the number of milliseconds to delay or sleep.
void LightLed (int nMilliSeconds)
{
RegPinNo myLed[] = { 0x01, 0x12, REGPINNOEOS }; // LED is addressed through Register 0, Pin 0 and Register 1, Pin 1 (zero based)
SetRegPins(myLed); // turn on the LED
Sleep(nMilliSeconds); // delay for a time with the LED lit
ClearRegPins(myLed); // turn the LED back off
}
Edit - A Refinement
A more efficient implementation that would allow multiple pins to be set in a particular register at the same time would be to define the use of RegPinNo as being an unsigned short` with the upper byte being the register number and the lower byte being the pins to manipulate as a bit mask for the byte.
With this approach you would have a SetRegPins() function that would look like the following. A similar change would be needed for the other functions.
void SetRegPins(RegPinNo *x)
{
int i;
for (i = 0; x[i] != REGPINNOEOS; i++) {
byte bRegNo = (x[i] >> 8) & 0x07; // get the register number, 0 - 7
byte bPinNo = x[i] & 0xFF; // get the pin mask
_PTAD[bRegNo].Byte |= bPinNo;
}
}
And the typedefs would look like:
typedef unsigned short RegPinNo; // upper byte indicates register number 0 - 7, lower byte provides pin mask
const byte REGPINNOEOS = 0xffff; // the end of string for a RegPinNo array.
And these elements would be used like:
void LightLed (int nMilliSeconds)
{
RegPinNo myLed[] = { 0x0002, 0x0103, REGPINNOEOS }; // LED is addressed through Register 0, Pin 1 and Register 1, Pin 0 and Pin 1 (zero based)
SetRegPins(myLed); // turn on the LED
Sleep(nMilliSeconds); // delay for a time with the LED lit
ClearRegPins(myLed); // turn the LED back off
}
I am new to the Cosmic compiler and STM8.
In iostm8s103.h the Switch control register is defined as
volatile char CLK_SWCR #0x50c5;
How do I address the switch busy bit (SWBSY bit 0) in that register?
I need to wait until the switch busy bit is clear. (While bit)
It is strange that I cannot find an example for the Cosmic compiler.
With the micro-controller, using volatile registers is simple.
#include <iostm8s103.h>
CLK_SWCR |= SWBSY; // to set the bit 0
CLK_SWCR &= ~SWBSY; // to reset the bit 0
In the iostm8s103.h, the register is defined as follow:
volatile char CLK_SWCR #0x50c5; /* Switch Control reg */
So, to wait while BUSY, with that iostm8s103.h, the code looks like:
while ((CLK_SWCR | SWBSY) != 0);
If using the stm8s.h instead of iostm8s103.h, the CLK registers
are defined as struct.
So, to wait while BUSY, with that stm8s.h, the code looks like:
while ((CLK->SWCR | CLK_SWCR_SWBSY) != 0);
or
while (CLK->SWCR & CLK_SWCR_SWBSY);
void Sound(int f)
{
USHORT B=1193180/f;
UCHAR temp = In_8(0x61);
temp = temp | 3;
Out_8(0x61,temp);
Out_8(0x43,0xB6);
Out_8(0x42,B&0xF);
Out_8(0x42,(B>>8)&0xF);
}
In_8/Out_8 reads/writes 8 bit to/from a specified port(implementation details omitted).
How does it make PC beep?
UPDATE
Why &0xF is used here? Shouldn't it be 0xFF?
The PC has a 8255 timer chip, which is controlled using the ports 0x61, 0x43 and 0x42.
When port 0x61 bit 0 is set to 1, this means "turn on the timer that is connected to the speaker".
When port 0x61 bit 1 is set to 1, this means "turn on the speaker".
This is done in the first paragraph of your code.
The second part puts the "magic value" 0xB6 on port 0x43, which means that the following two bytes arriving at port 0x42 will be interpreted as the divisor for the timer frequency. The division's resulting frequency (1193180 / divisor) will then be sent to the speaker.
http://gd.tuwien.ac.at/languages/c/programming-bbrown/advcw3.htm#sound