Timers Programming Model
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
21-25
21.4.3 Software Watchdog Timers
This section describes the software WDT registers, which include:
System Watchdog Control Register 0–4 (SWCRR[0–4]), see page 21-25.
System Watchdog Count Register 0–4 (SWCNR[0–4]), see page 21-26.
System Watchdog Service Register 0–4 (SWSRR[0–4]), see page 21-27.
Note:
The watchdog timers use the following base addresses:
System Watchdog Timer 0 = 0xFFF25000
System Watchdog Timer 1 = 0xFFF25100
System Watchdog Timer 2 = 0xFFF25200
System Watchdog Timer 3 = 0xFFF25300
System Watchdog Timer 4 = 0xFFF25400
21.4.3.1
System Watchdog Control Register 0–4 (SWCRR[0–4])
SWCRR[0–4] control the software watchdog timer period and configure WDT operation.
SWCRR can be read at any time but can be written only once after system reset. Table 21-7
defines the SWCRR[0–4] bit fields.
SWCRR[0–4]
System Watchdog Control Register 0–4
Offset 0x04
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
SWTC
Type
R/W
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
—
SWEN SWRI SWPR
Type
R/W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
Table 21-7. SWCRR[0–4] Bit Descriptions
Name
Reset
Description
Settings
SWTC
31–16
0xFFFF
Software Watchdog Time Count
The SWTC field contains the modulus that is reloaded into the watchdog counter by a service
sequence. When a new value is loaded into SWCRR[SWTC], the software watchdog timer is not
updated until the servicing sequence is written to the SWSRR. If SWCRR[SWEN] is loaded with
0, the modulus counter does not count. The new value is also used at the next and all subsequent
reloads. Reading the SWCRR register returns the value in the System Watchdog Control
Register. Reset initializes the SWCRR[SWTC] field to $FFFF.
Note:
The prescaler counter is reset anytime a new value is loaded into the watchdog counter
and also during reset.
—
15–3
0
Reserved. Write to zero for future compatibility.
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 ...