Emerson MVME3100 Personal Computer User Manual


 
Memory Maps
MVME3100 Single Board Computer Installation and Use (6806800M28C)
121
INTS: Interrupt status.
RSVD: Reserved for future implementation.
6.1.16.3 Compare Registers
The tick timer counter is compared to the Compare register. When they are equal, the tick
timer interrupt is asserted and the overflow counter is incremented. If the clear-on-compare
mode is enabled, the counter is also cleared. For periodic interrupts, this equation should be
used to calculate the compare register value for a specific period (T):
Compare register value = T (us)
When programming the tick timer for periodic interrupts, the counter should be cleared to
zero by software and then enabled. If the counter does not initially start at 0, the time to the
first interrupt may be longer or shorter than expected. The rollover time for the counter is 71.6
minutes.
Table 6-19 Tick Timer Compare Registers
Tick Timer 1 Compare Register - 0xE202 0014 (32 bits)
Tick Timer 2 Compare Register - 0xE202 0024 (32 bits)
Tick Timer 3 Compare Register - 0xE202 0034 (32 bits)
Tick Timer 4 Compare Register - 0xE202 0044 (32 bits)
BIT 31 0
FIELD Tick Timer Compare Value
OPER R/W
RESET 0