baseaddress is the address at which the adapter has been installed, e.g. 310H
ownaddress I2C address to which the adapter is to respond in slave mode. This forms the upper 7 bits of the 8 bit address, the lowest bit being the read (1) or write (0) bit. This means that if ownaddress = 57H the card will respond to a write address of AEH and a read address of AFH.
Statuswait is a period of time (in microseconds) to wait for the required bus status. If this
sclk is clock rate (bit rate for the I2C serial bus) when operating as a master.
Value of sclk | Approximate |
0 | 90 |
1 | 45 |
2 | 11 |
3 | 1.5 |
Parameters returned | none. |
Prerequisites | none. |
Functional description | This function characterises the PC and initialises adapter ready for I2C |
| transfers. |
sendaddress |
|
Functional specification | Int sendaddress (int slaveaddress, int setnack) |
| slaveaddress is the address to be accessed via the I2C, e.g. A0H |
| setnack 1 for no acknowledge 0 for acknowledge – see Functional |
| Description |
Parameters returned | ErrCode. If the transfer time out occurs error code 8001H is returned |
| otherwise the status is returned. |
Prerequisites | adapter must be configures by running setup. |
Functional description | The function waits for the bus to be free. Then sends the slave address |
| with the appropriate acknowledge. |
| The acknowledge is set ready for the data transfer after the address and |
| hence in read mode (odd address being sent) if only one byte is to be |
| read the setnack parameter must equal 1. If more than one byte is to be |
| read or if in write mode (even address being sent) then setnack must |
| equal 0. |
writebyte |
|
Function specification | Int writebyte (int wrData) |
| wrData is the byte of data to be written. |
Paramteres returned | ErrCode. If the transfer time out occurs error code 8004H is returned |
| otherwise the status is returned. |
Prerequisites | Adapter must be configured using setup, start and write address sent by |
| sendaddress. |
Functional description | The function writes the data to the adapter and then waits for it to be |
| sent. Should a |
| code 8004H is returned, otherwise the status is returned. Writebyte is |
| compatible with both master write and slave write modes. |
readbyte |
|
Function specification | Int readbyte (int setnack) |
Revision 1.7 | Page 16 of 27 |
09/12/1999 |
|
