KL1512 - Process data exchange
Control byte in process data exchange (REG=0)
During process data exchange, the control byte is used to trigger various actions in the KL1512 counter terminal:
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Name | REG=0 | 0 | CNT_SET | CNT_INH | 0 | CNT_OVL | CNT_CLR | CNT_DEC |
Bit | Function |
|---|---|
REG=0 | 0 for Process data mode |
0 | Not used |
CNT_SET | The counter is set to the value that is specified via the process data. |
CNT_INH | The counter is stopped, as long as this bit is active. The present counter value is saved. |
0 | Not used |
CNT_OVL | If this bit is set, the counter is stopped, if it reaches 0xFFFF while counting forwards if it reaches 0x0000 while counting backwards |
CNT_CLR | The counter is set to the value 0x0000. Setting of the counter is edge controlled. |
CNT_DEC | If this bit is set, the counter is decremented with every positive edge. |
Status byte in process data exchange (REG=0)
The status byte is transferred from the terminal to the controller. The status byte contains various status bits of the KL1512 counter terminal
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
Name | REG=0 | 0 | SET_ACK | INH_ACK | 0 | OVL_ACK | CLR_ACK | DEC_ACK |
Bit | Function |
|---|---|
REG=0 | 0 for Process data mode |
0 | Not used |
SET_ACK | Acknowledgement for CNT_SET: The data for setting the counter was taken over by the terminal. |
INH_ACK | Acknowledgement for CNT_INH: The counter is stopped. |
0 | Not used |
OVL_ACK | Acknowledgement for CNT_OVL: If this bit is set, the counter is stopped, if it reaches 0xFFFF while counting forwards if it reaches 0x0000 while counting backwards |
CLR_ACK | Acknowledgement for CNT_CLR: The counter is set to the value 0x0000. Setting of the counter is edge controlled. |
DEC_ACK | Acknowledgement for CNT_DEC: If this bit is set, the counter is decremented with every positive edge. |