MSC8144E Reference Manual, Rev. 3
21-26
Freescale
Semiconductor
Timers
21.4.3.2
System Watchdog Count Register 0–4 (SWCNR[0–4])
SWCNR[0–4] provide visibility to the WDT counter values. Writes to SWCNR have no effect
and terminate without transfer error exception.
SWEN
2
0
Watchdog Enable
SWCRR[SWEN] bit enables the watchdog
timer. It should be cleared by software after a
system reset to disable the software watchdog
timer. When the watchdog timer is disabled, the
watchdog counter and prescaler counter are
held in a stopped state.
0
Watchdog timer disabled.
1
Watchdog timer enabled.
SWRI
1
1
Software Watchdog Reset/Interrupt Select
Depending on the SWCRR[SWRI]
programming, WDT timer causes a hard reset
or machine check interrupt to the core.
0
Software watchdog timer causes a machine
check interrupt to the core.
1
Software watchdog timer causes a hard
reset (this is the default value after soft
reset).
SWPR
0
1
Software Watchdog Counter Prescale
Controls the divide-by-65536 WDT counter
prescaler.
0
The WDT counter is not prescaled.
1
The WDT counter clock is divided by
65536.
SWCNR[0–4]
System Watchdog Count Register 0–4
Offset 0x08
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
—
Type
R
Reset
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
SWCN
Type
R
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Table 21-8. SWCNR[0–4] Bit Descriptions
Name
Reset
Description
—
31–16
0
Reserved. Write to zero for future compatibility.
SWCN
15–0
0xFFFF
Software Watchdog Count Field
The read-only SWCNR[SWCN] field reflects the current value in the watchdog counter. Writing to
the SWCNR register has no effect, and write cycles are terminated normally. Reset initializes the
SWCNR[SWCN] field to $FFFF. Reading the 16 LS bits of 32-bit SWCNR register with two 8-bit
reads is not guaranteed to return a coherent value.
Table 21-7. SWCRR[0–4] Bit Descriptions
Name
Reset
Description
Settings
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...