1-48
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Programming Issues
1
1.
Set up Tick Timer:
2.
Set up local bus interrupter:
Step
Register and Address
Action and Reference
1
Prescaler Control register
$FFF4004C
If not already initialized by the debugger, initialize as
follows: Prescaler register = 256–Bclock (MHz). This
gives a 1 MHz clock to the tick timers. Bclock is the bus
clock rate, such as 25MHz.
256–25 = $E7.
2
Tick Timer 1
Compare register
$FFF40050
For periodic interrupts, set the Compare Register value =
Period (s). For example, if you want an interrupt every
millisecond, set the register value to 1000 ($3E8). Refer
to the
Tick Timer 1 Compare Register
description in
Chapter 2.
3
Tick Timer 1
Counter register
$FFF40054
Write a zero to clear the register.
4
Tick Timer 1
Control register
$FFF40060 (8 bits)
Write $07 to this register (set bits 0, 1, and 2). This
enables the Tick Timer 1 counter to increment, resets the
count to zero on compare, and clears the overflow
counter.
Step
Register and Address
Action and Reference
5
Vector Base register
$FFF40088 (8 of 32 bits)
If not already initialized by the debugger, set Interrupt
Base register 0 by writing to bits 28-31. Refer to the
Vector Base Register
description and to Table 2-4, Local
Bus Interrupter Summary, in Chapter 2.
6
Interrupt Level register 1
(bits 0-7)
$FFF40078 (8 of 32 bits)
Write desired level of Tick Timer 1 interrupt to bits 0-2.
7
Local Bus Interrupter
Enable register
$FFF4006C (8 of 32 bits)
Set bit 24 (ETIC1) to 1 to enable Tick Timer 1 interrupts.
8
I/O Control Register 1
$FFF40088 (8 of 32 bits)
Write a 1 to bit 23 to enable interrupts from the
VMEchip2. A 0 masks all interrupts from the VMEchip2.
Summary of Contents for MVME1X7P
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Page 90: ...1 64 Computer Group Literature Center Web Site Programming Issues 1 ...
Page 248: ...3 50 Computer Group Literature Center Web Site PCCchip2 3 ...
Page 286: ...4 38 Computer Group Literature Center Web Site MCECC Functions 4 ...
Page 288: ...A 2 Computer Group Literature Center Web Site Summary of Changes A ...
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