Counter / Timers - VersaLogic Iguana VL-EPIC-25 Reference Manual

Counter / Timers

The Iguana includes two uncommitted 8254 type counter/timer channels for general program use.
External control signals for the two channels are available on connector J25.
J25 Signal
Pin Direction*
36 Output
37 Input
38 Output
39 Input
—
40
* Relative to VL-EPIC-25
The Custom Programming appendix discusses how to use and configure these timers using the
following registers.
Register
IRQCTRL
IRQSTAT
TMCNTRL
VL-EPIC-25 Reference Manual
Table 20: Counter Timer Pinout
Signal
Name Function
OCTC3 Timer 3 Counter Output
ICTC3 Timer 3 Clock Input
OCTC4 Timer 4 Counter Output
ICTC4 Timer 4 Clock Input
GND Ground
Read/Write Address
R/W CA3h
R-Status/Write-Clear CA4h
R/W CA5h
Interfaces and Connectors
VL-CBR-4004 VL-CBR-4004
Connector
Pin (Label)
1 (IO29)
J9
2 (IO30)
3 (IO31)
4 (IO32)
5 (GND4)
Name
Interrupt Control Register
Interrupt Status Register
Timer Control Register
50