Parameters are: |
|
int controladdress | address of I2C control register. This is equal to 1+(base address of adapter set |
| by links on circuit board). |
Value Returned: |
|
int <status> | where status is an integer from 0x00 to 0xFF which indicates the current status |
| of I2C Communications Adapter. See Appendix A for details of the status values |
| returned. |
I2C status on exit from routine:
The status of the I2C Communications Adapter will not be affected by using the getstatus function.
Example Usage: (see also sample programs) #include <stdio.h.>
#include <dos.h>
#include <i2c.h> main
{
int status, base, controladdress;
base = 0x310;/*Adapter’s base address = 0x310 (hex) */ controladdress = base + 1;
Status = getstatus (controladdress);
printf(“I2C Communications Adapter Status = %x\n”, status);
}
/*This will read the I2C Communications Adapter’s current status */
5.1.3.I2C Address and Start Sending Routine
Name: | sendaddress (base, slv, setnack) |
Usage: | sendaddress(base, slv, setnack) |
Function: | procedure to send Start and slave address of device that is to be communicated |
| with. |
Parameters are: |
|
int base | the base address of the I2C Communications Adapter set by links on circuit |
| board. |
int slv | the slave address of the device which is to be communicated with. This will be an |
| even number if the adapter is to write to the slave, add 1 to get an odd number if |
| the adapter is to read from the slave. |
int setnack | this controls whether the I2C Communications Adapter transmits an |
| Acknowledge down the I2C Bus on reception of a byte. The last byte received |
| during a transfer must not be acknowledged, in all other cases acknowledge is |
| enabled, if setnack = 1 then acknowledge is disabled. Therefore, if a read (odd |
| numbered) address is being sent AND only 1 byte is to be read, setnack should |
| be set to = 1; in all other cases it must be set = 0. |
Value Returned:none. |
|
I2C status on exit from routine
| The status of the I2C/ the Communications Adapter will be either 0x00 - bus busy |
| and unread data in the data register or 0x80 - bus busy and no unread data in the |
| data register when a Start and Slave Address have been successfully transmitted |
| (see Appendix A for details of Status Codes). |
Example Usage: | (see also sample programs) |
#include <stdio.h> |
|
#include <dos.h> | /* Adapter’s base address = 0x310 (hex) */ |
| /* compiler supports DOS I/O functions */ |
#include <i2c.h> | /* This contains the I2C routines */ |
main |
|
Revision 1.7 | Page 7 of 27 |
09/12/1999 |
|
