Self-Contained Ibm Performance Monitor for a Personal Computer
Original Publication Date: 1988-Dec-01
Included in the Prior Art Database: 2005-Feb-15
A performance monitor adapter card for a PC interrogates the PC I/O channel for 2 programmable events and 1 external event. The 2 programmable events are PC memory addresses that may be written to or read from. When an event occurs, a timer value, the PC data bus, and identification information is captured and automatically gated into battery backed up on-card RAM. In this implementation, up to 4096 events can be captured before the memory is exhausted. The implementation also supports optional memory wrap around. The figure shows the adapter-card design. The adapter is controlled via external registers 160, 90, 80, 70 and 60 through a terminate-and-stay-resident PC program.