© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
User manual
Rev. 01 — 12 January 2006
35
Philips Semiconductors
UM10161
Volume 1
Chapter 3: System control block
3.10.1 Reset Source Identification Register (RSIR - 0xE01F C180)
This register contains one bit for each source of Reset. Writing a 1 to any of these bits
clears the corresponding read-side bit to 0. The interactions among the four sources are
described below.
Fig 10. Reset block diagram including the wake-up timer
C
Q
S
ABP read of
PDBIT
in PCON
power
down
C
Q
S
F
OSC
to CPU
WAKE-UP TIMER
watchdog
reset
external
reset
START
COUNT 2
n
oscillator
output (F
OSC
)
reset to the
on-chip circuitry
reset to
PCON.PD
write “1”
from APB
Reset
EINT0 wake-up
EINT1 wake-up
EINT2 wake-up
PLL
Table 27:
Reset Source identification Register (RSIR - address 0xE01F C180) bit description
Bit
Symbol Description
Reset
value
0
POR
Power-On Reset (POR) event sets this bit, and clears all of the other bits
in this register. But if another Reset signal (e.g., External Reset) remains
asserted after the POR signal is negated, then its bit is set. This bit is not
affected by any of the other sources of Reset.
see text
1
EXTR
Assertion of the RESET signal sets this bit. This bit is cleared by POR,
but is not affected by WDT reset.
see text
2
WDTR
This bit is set when the watchdog timer times out and the WDTRESET
bit in the Watchdog Mode Register is 1. It is cleared by any of the other
sources of Reset.
see text
7:3
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
NA