getstatus |
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Function specification: | Int getstatus ( ) |
Parameters returned | I2Cstatus, the current value of the bus status. |
Prerequisites | Adapter must be configured using setup. |
Functional description | The function reads status word from the adapter and returns it. |
recover |
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Function specification: | Int recover |
Parameters returned | ErrCode. If the bus recovery failed error code 8006H is returned |
| otherwise the status is returned. |
Prerequisites | Adapter must be configured using setup. |
Functional description | This function issues two consecutive stop commands on the bus, with a |
| delay in between. It then clears the adapter registers and reads the |
| status. This should normally set the adapter into a known idle state when |
| a bus error or other problem has occurred. |
| If the status does not indicate bus free or the Bus Error bit is still set then |
| 8006H is returned otherwise the status is returned. |
sendbytes
Function specification Int sendbytes (int far *transferarray)
The far pointer must point to a single dimensional array the format of which is detailed below. The calling function must have initialised elements 0, 1 and 2 prior to calling the function.
Element no | Element name | Description |
0 | slaveaddress | Slaveaddress is the address to be accessed via the I2C |
|
| Bus, this is in hexadecimal e.g. A0H. |
1 | wordaddress | Wordaddress is the offset within the slave to which the |
|
| first byte of data is to be written, see transmission format |
|
| for more details. |
2 | nobytes | The number of bytes (n) to be sent. Min value 1. |
3 | byte 0 | First byte to be sent. |
| “ |
|
| “ |
|
| byte n | Last byte to be sent. |
Parameters returned | bsent, the number of bytes actually sent. |
Prerequisites | Adapter must be configured using setup. Array elements 0, 1 and 2 |
| must be initialised. Usually elements 3 to n would also be initialised. |
| Array must be |
| parameters and data concerned. |
Transmission format | There are two transmission formats, these are: |
i.
If transmission format i.) is required set the wordaddress to a number greater than FFH.
ii.
If transmission format ii.) is required set the wordaddress to a number less than or equal to FFH.
Functional description | The function determines the required transmission format and then |
| sends a start code and the slave address. If transmission format ii) has |
| been selected the wordaddress is sent. |
| The data bytes are then transmitted sequentially. |
| Should a |
| transmission is terminated by a stop and the number of bytes actually |
| transmitted is returned. |
Revision 1.7 | Page 18 of 27 |
09/12/1999 |
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