PXR40RM Datasheet, PDF (498/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

Software Watchdog Timer (SWT)
continues to run. In stop mode, operation of the counter is controlled by the STP bit in the SWT_MCR. If
the STP bit is set, the counter is stopped in stop mode, otherwise it continues to run.
18.2 External Signal Description
The SWT module does not have any external interface signals.
18.3 Memory Map and Register Definition
The SWT programming model has seven 32-bit registers. The programming model can only be accessed
using 32-bit (word) accesses. References using a different size are invalid. Other types of invalid accesses
include: writes to read only registers, incorrect values written to the service register when enabled,
accesses to reserved addresses and accesses by masters without permission. If the RIA bit in the
SWT_MCR is set then the SWT generates a system reset on an invalid access otherwise a bus error is
generated. If either the HLK or SLK bits in the SWT_MCR are set then the SWT_MCR, SWT_TO,
SWT_WN, SWT_SK registers are read only.
18.3.1 Memory Map
The SWT memory map are shown in Table 18-1. The base address for each SWT is given in Table 18-1.
Table 18-1. SWT Memory Map
Address
Offset
Register
Bits Access Reset Value Section/Page
0x0000
SWT_MCR—SWT Module Control Register 32
R/W 0xFF00_0*0B 18.3.2.1/2
0x0004
SWT_IR—SWT Interrupt Register
32
R/W 0x0000_0000 18.3.2.2/5
0x0008
SWT_TO—SWT Time-out Register
32
R/W 0x0005_FCD0 18.3.2.3/5
0x000C
SWT_WN—SWT Window Register
32
R/W 0x0000_0000 18.3.2.4/6
0x0010
SWT_SR—SWT Service Register
32
R/W 0x0000_0000 18.3.2.5/6
0x0014
0x0018
SWT_CO—SWT Counter Output Register
SWT_SK—SWT Service Key Register
32
R 0x0000_0000 18.3.2.6/7
32 R/W¹ 0x0000_0000 18.3.2.7/8
0x001C–0x3FFF Reserved
NOTES:
1 _{If neither HLK or SLK lock bit in the SWT_MCR is set, the SWT_SK can be initialized by software to a non-zero value.}
18.3.2 Register Descriptions
The following sections detail the individual registers within the SWT programming model.
18.3.2.1 SWT Control Register (SWT_MCR)
The SWT_MCR contains fields for configuring and controlling the SWT. This register is read only if either
the SWT_MCR[HLK] or SWT_MCR[SLK] bits are set.
18-2
PXR40 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor