Processor Users Manual

4-35 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA
Part II. ConÞguration and Reset
4.3.2.8 System Protection Control Register (SYPCR)
The system protection control register, shown in Figure 4-30, controls the system monitors,
software watchdog period, and bus monitor timing. SYPCR can be read at any time but can
be written only once after system reset.
Table 4-14 describes SYPCR Þelds.
Bits 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Field SWTC
Reset 1111_1111_1111_1111
R/W R/W
Addr 0x10004
Bits 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Field BMT PBME LBME Ñ SWE SWRI SWP
Reset 1111_1111 0 0 00_0 1 1 1
R/W R/W
Addr 0x10006
Figure 4-30. System Protection Control Register (SYPCCR)
Table 4-14. SYPCR Field Descriptions
Bits Name Description
0Ð15 SWTC Software watchdog timer count. Contains the count value for the software watchdog timer.
16Ð23 BMT Bus monitor timing. DeÞnes the time-out period for the bus monitor, the granularity of this Þeld is 8
bus clocks. (BMT = 0xFF is translated to 0x7f8 clock cycles). BMT is used both in the 60x and local
bus monitors.
Note that the value 0 in invalid; an error is generated for each bus transaction.
24 PBME 60x bus monitor enable.
0 60x bus monitor is disabled.
1 The 60x bus monitor is enabled.
25 LBME Local bus monitor enable.
0 Local bus monitor is disabled.
1 The local bus monitor is enabled.
26Ð29 Ñ Reserved, should be cleared.
29 SWE Software watchdog enable. Enables the operation of the software watchdog timer. It should be
cleared by software after a system reset to disable the software watchdog timer.
30 SWRI Software watchdog reset/interrupt select.
0 Software watchdog timer and bus monitor time-out causes a machine check interrupt to the core.
1 Software watchdog timer and bus monitor time-out causes a soft reset (this is the default value
after soft reset).
31 SWP Software watchdog prescale. Controls the divide-by-2,048 software watchdog timer prescaler.
0 The software watchdog timer is not prescaled.
1 The software watchdog timer clock is prescaled.