User guide

CIF Peripheral Model - SimpleTimer
128 CoMET Version 5.9 – Tutorial
Metrix Output
A Metrix trace shows the timing and details of instructions executed by the VPM. Probes
show changes in Nets and Ports, such as the IrqNet and the StdBus1 Net.
An extract from a sample Metrix output is shown below. This is around the point at which the
SimpleTimer test target code writes MATCH_TEST_VALUE (0x0000FF00) to MTR1 (at
address 0x90000028).
The following Metrix trace excerpt shows the SimpleTimer1 module instance generating its
first interrupt and the VPM servicing it.
The above trace shows:
• the interrupt taking place at clock time 65379
• the VPM servicing the interrupt (ABORT PC) at clock time 65384, 5 ticks after it took
place.
This latency is consistent with the default VPM Minimum OIL (Optimum Interrupt Latency)
setting of 10 ticks. If you reduce the VPM Minimum OIL setting, the VPM may service the
interrupt a few ticks earlier in simulated time, but the additional interrupt checking may
reduce performance, resulting in a longer simulation in real time.