© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
User manual
Rev. 01 — 15 August 2005
39
Philips Semiconductors
UM10139
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 wakeup timer
C
Q
S
VBP Read
of PDBIT
in PCON
Power
down
C
Q
S
F
OSC
to PLL
WAKEUP TIMER
Watchdog
reset
External
reset
EINT0 Wakeup
EINT1 Wakeup
EINT2 Wakeup
EINT3 Wakeup
RTC Wakeup
START
COUNT 2
n
Oscillator
output
(F
OSC
)
Reset to the
on-chip
circuitry
Reset to
PCON.PD
Write “1”
from VPB
Reset
USB Wakeup
BOD Wakeup
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 or BOD reset.
see text