Hardware manual

EUROCOM-17-5xx 3 Programmers Reference

Hardware Manual 65

3.6 CIO Counter/Timers

The EUROCOM-17-5xx offers six independent, programmable 16-bit

counter/timers integrated in two CIOs. Three of these counters, located

in the user CIO ($FEC1.0000), can be used as general-purpose devices

with up to four external access lines per counter/timer (count input,

output, gate, and trigger). PortA and C of this CIO are connected to X102

for user application. Refer to Table8: ‘Pin Assignment of Connector

X102’.

The three counters located in the system CIO are used for internal control

tasks.

The peripheral clock of both CIOs is connected to a 5MHz source. The

interrupt request outputs of both CIOs are connected to the LIRQ6 input

of the VIC. The system CIO has the higher interrupt priority in the daisy

chain. Local interrupt control register 6 (LIRQ6) of the VIC has to be

programmed for an active low, level-sensitive input. The vectors are

supplied by the CIOs. The VIC has to be programmed to generate

interrupts on level 5 to the CPU. Only CPU IACK level 5 cycles are

routed to the CIO devices.

The address assignments of both CIOs are different! The address

assignment of the user CIO (at address $FEC1.0000) is the same as on the

EUROCOM-6.

The CIOs and the serial controller CL-CD2401 are default connected to

LIRQ6 of the VIC with the CL-CD2401 of the higher interrupt priority.

Table36: Address Assignment of the CIOs

Address Description

$FEC3.0000 Port C Data Register System CIO

$FEC3.0001 Port B Data Register System CIO

$FEC3.0002 Port A Data Register System CIO

$FEC3.0003 Control Register System CIO

$FEC1.0000 Port C Data Register User CIO

$FEC1.0001 Port A Data Register User CIO

$FEC1.0002 Port B Data Register User CIO

$FEC1.0003 Control Register User CIO