13-22
MPC8260 PowerQUICC II UserÕs Manual
MOTOROLA
Part IV. Communications Processor Module
13.6.5
SET
TIMER
Command
The
SET
TIMER
command is used to enable, disable, and conÞgure the 16 timers in the RISC
timer table and is issued to the CPCR. This means the value 0x29E1008 should be written
to CPCR. However, before writing this value, the user should program the TM_CMD Þelds.
See Section 13.6.2, ÒRISC Timer Command Register (TM_CMD).Ó
13.6.6 RISC Timer Initialization Sequence
The following sequence initializes the RISC timers:
1. ConÞgure RCCR to determine the preferred tick interval for the entire timer table.
The TIME bit is normally set at this time but can be set later if all RISC timers need
to be synchronized.
2. Determine the maximum number of timers to be located in the timer table.
ConÞgure the TM_BASE in the RISC timer table parameter RAM to point to a
location in the dual-port RAM with 4
´
n
bytes available, where
n
is the number of
timers. If
n
is less than 16, use timer 0 through timer
n
Ð1 to save space.
3. Clear the TM_CNT Þeld in the RISC timer table parameter RAM to show how many
ticks elapsed since the RISC internal timer was enabled. This step is optional.
4. Clear RTER, if it is not already cleared. Write ones to clear this register.
5. ConÞgure RTMR to enable the timers that should generate interrupts. Ones enable
interrupts.
6. Set the RISC timer table bit in the SIU interrupt mask register (SIMR_L[RTT]) to
generate interrupts to the system. The SIU interrupt controller may require other
initialization not mentioned here.
7. ConÞgure the TM_CMD Þeld of the RISC timer table parameter RAM. At this
point, determine whether a timer is to be enabled or disabled, one-shot or restart, and
what its timeout period should be. If the timer is being disabled, the parameters
(other than the timer number) are ignored.
8. Issue the
SET
TIMER
command by writing 0x29E1_0008 to the CPCR.
9. Repeat the preceding two steps for each timer to be enabled or disabled.
13.6.7 RISC Timer Initialization Example
The following sequence initializes RISC timer 0 to generate an interrupt approximately
every second using a 133-MHz general system clock:
1. Write 111111 to RCCR[TIMEP] to generate the slowest clock. This value generates
a tick every 64,512 clocks, which is every 485 µs at 133 MHz.
2. ConÞgure the TM_BASE in the RISC timer table parameter RAM to point to a
location in the dual-port RAM with 4 bytes available. Assuming the beginning of
dual-port RAM is available, write 0x0000 to TM_BASE.
Summary of Contents for MPC8260 PowerQUICC II
Page 1: ...MPC8260UM D 4 1999 Rev 0 MPC8260 PowerQUICC II UserÕs Manual ª ª ...
Page 66: ...lxvi MPC8260 PowerQUICC II UserÕs Manual MOTOROLA ...
Page 88: ...1 18 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part I Overview ...
Page 120: ...2 32 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part I Overview ...
Page 138: ...Part II iv MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part II Configuration and Reset ...
Page 184: ...4 46 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part II ConÞguration and Reset ...
Page 202: ...Part III vi MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 266: ...8 34 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 382: ...10 106 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 392: ...11 10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 430: ...Part IV viii MOTOROLA Part IV Communications Processor Module ...
Page 490: ...14 36 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 524: ...17 10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 556: ...18 32 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 584: ...19 28 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 632: ...21 24 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 652: ...22 20 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 668: ...23 16 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 758: ...27 28 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 780: ...28 22 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 874: ...29 94 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 920: ...31 18 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 980: ...A 4 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Appendixes ...
Page 1002: ...Index 22 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA INDEX ...
Page 1006: ......