/* This will read a byte of data from a slave previously addressed */ /* by and with acknowledge already disabled by sendaddress. */ /* After reading the data, acknowledge will be
5.1.5.Write Data Byte to Slave Routine
Name: | writebyte(base, data) |
Usage: | writebyte(base, data) |
Function: | procedure to write a byte of data to a slave device whose slave address has |
| already been sent by sendaddress. |
Parameters are: |
|
int base | The base address of the I2C Communications Adapter set by links on circuit |
| board. |
int data | The byte of data which is to be written to the slave device. |
Value Returned:none. |
|
I2C status on exit from routine:
| The status of the I2C Communications Adapter will be 0x00 - bus busy and data |
| in the data register transmitted successfully. (See Appendix A for details of |
| Status Codes). |
Example Usage: | (see also sample programs) |
#include <stdio.h> |
|
#include <dos.h> | /* Optional, but recommended if your compiler */ |
| /* supports DOS I/O functions */ |
#include <i2c.h> | /* This contains the I2C routines */ |
main |
|
{ |
|
int base, data; |
|
base = 0x310; | /* Adapter’s base address = 0 x 310- (hex) */ |
data = 0x69; | /* Data byte which is to be transmitted */ |
writebyte (base, data) ;
printf(“Data has been transmitted\n”);
}
/* This will write a byte of data to a slave previously addressed */ /* by sendaddress. */
5.1.6.Send an I2C Stop Routine
Name: | sendstop(controladdress) |
Usage: | sendstop(controladdress); |
Function: | procedure to send a stop (end of communication signal) down the I2C Bus, |
| ending a transmission or reception with a slave which was addressed previously |
| by sendaddress. |
Parameters are: |
|
int controladdress | the address of the I2C Communications Adapter control register, equal to |
| 1+(base address set by links on circuit board). |
Value Returned:none. |
|
I2C status on exit from routines:
| The status of the I2C/ the Communications Adapter will be 0x81 - bus idle and no |
| unread/untransmitted data in the data register. Note - this may not be the case in |
| a system where there is another master as well as the I2C Communications |
| Adapter, since this other master may well have taken control of the bus by the |
| time a program next uses getstatus to read the status register. (See Appendix A |
| for details of Status Codes). |
Example Usage: | (see also sample programs) |
#include <stdio.h> |
|
Revision 1.7 | Page 9 of 27 |
09/12/1999 |
|
