HP 27130A Technical Reference Manual page 47

HP 27130A
Table 3-7. CTC Timer Outputs
TIMER DRIVEN DEVICE
CTC CTC OUTPUT
INPUT
NO. CH. MNEMONIC MNEMONIC FUNCTION
0 0
. IRQH
IRQH of MIC Request hold-off for DMA
0 1 BRG1 SID 0
MUX card channel 1 baud-
RXCB- & TXCB- rate clock
0 2 BRGO SID 0
MUX card channel
o
baud-
RXCA- & TXCA- rate clock
0 3
INTERNAL
Cause zero Real-time clock for
count interrupt
firmware
to Z-80B CPU
1 0 BRG2 SID 1
MUX card channel 2 baud-
RXCA- & TXCA- rate clock
1 1 BRG3 SID 1
MUX card channel 3 baud-
RXCB- & TXCB- rate clock
1 2
BRG4 SID 2 MUX card channel 4 baud-
RXCA- & TXCA- rate clock
1
3
Not avai lable Counter value can be
read <polled)
by
Z-80B
CPU
3-20