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Functional description | The function determines the required transfer format, sends the appropriate | ||||
| sequence of start(s) and slave address(es) and checks for acknowledges | ||||
| where necessary. | ||||
| If the slave fails to acknowledge then a stop is sent and nobytesread is | ||||
| returned equal to 0. | ||||
| The first data byte read is the slave read address sent (see readbyte | ||||
| description). This is discarded, it is not returned in the transfer array. The data | ||||
| bytes are then read and stored in the transfer array. At the appropriate point | ||||
| acknowledges are ceased - for the last and the last but one byte to be | ||||
| transferred. | ||||
| A stop is sent after the last byte has been read. On completion the number of | ||||
| bytes read is returned. | ||||
| Should a | ||||
| of bytes successfully read is returned. | ||||
| Getbytes can only be used in master read mode. | ||||
4.4.14. slavelastbyte |
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Function specification | void slavelastbyte( ) | ||||
Parameters returned | none. | ||||
Prerequisites | Adapter must be configured using setup. This function would normally only | ||||
| be called following the end of a transmission in slave write mode - when the | ||||
| adapter is being read as a slave, by another master, not when writing to a | ||||
| slave using the adapter. | ||||
Functional description | This function is used when the adapter is a slave being read by a master | ||||
| elsewhere on the bus - the adapter is in slave write mode. The function must | ||||
| be called immediately after the master indicates the last byte has been read | ||||
| (by not acknowledging that byte). This function is required to clear the I2C | ||||
| data lines so that the master can send a stop signal. | ||||
Issue 1.3 | Page 26 |
22/07/99