Intel PXA255 Personal Computer User Manual


 
3-30 Intel® PXA255 Processor Developer’s Manual
Clocks and Power Manager
3.5.8 Power Manager Scratch Pad Register (PSPR)
The PM contains a 32-bit register that can be used to save processor configuration information in
any desired format. The PSPR, shown in Table 3-14, is a holding register that is powered during
sleep mode and is reset by hardware, watchdog, and GPIO resets. During run and turbo modes, any
value can be written to PSPR. The value can be read after sleep mode exits. The value in PSPR can
be used to represent the processor’s configuration before sleep mode is invoked.
This is a read/write register. Ignore reads from reserved bits. Write zeros to reserved bits.
2VFS
VDD Fault Status.
0 – nVDD_FAULT pin has not been asserted since it was last cleared by a reset or the
CPU.
1 – nVDD_FAULT pin was asserted in Run or idle mode and caused the chip to enter
sleep mode; bit is set only after wake up.
This bit is not set when nVDD_FAULT is asserted while in sleep mode.
Cleared by hardware, watchdog, and GPIO resets.
1BFS
Battery Fault Status.
0 – nBATT_FAULT pin has not been asserted since it was last cleared by a reset or the
CPU.
1 – nBATT_FAULT pin has been asserted; bit is set only after wake up.
This bit can be set when nBATT_FAULT is asserted while in sleep mode.
Cleared by hardware, watchdog, and GPIO resets.
0SSS
Software Sleep Status.
0 – Software has not entered sleep mode through the sleep mode bit since the SSS
was last cleared by a reset or the CPU.
1 – Chip was placed in sleep mode by setting the sleep mode bit.
Cleared by hardware, watchdog, and GPIO resets.
Table 3-13. PSSR Bit Definitions (Sheet 2 of 2)
0x40F0_0004 PSSR Clocks and Power Manager
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
reserved
RDH
PH
reserved
VFS
BFS
SSS
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0
Bits Name Description
Table 3-14. PSPR Bit Definitions
0x40F0_0008 PSPR Clocks and Power Manager
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
SP
Reset
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Bits Name Description
[31:0] SP
Scratch Pad
32-bit word is preserved in sleep mode.
Cleared by hardware, watchdog, and GPIO resets.