
Philips Semiconductors
PNX15xx Series
Volume 1 of 1
Chapter 4: Reset
PNX15XX_SER_3
Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Product data sheet
Rev. 3 — 17 March 2006
4-6
5. If step 4 does not occur before the count reaches the WATCHDOG_COUNT
value an interrupt is issued to the TM3260 CPU and the second internal counter
(the interrupt counter) starts. The internal watchdog counter is reset and waits
the interrupt to be cleared.
6. A write with 0x1 to INTERRUPT_CLEAR stops the interrupt counter and restarts
the watchdog counter. Therefore for continuous watchdog timer operation start
back at step 5).
Here once the interrupt is asserted then the rst counter is reset to zero
7. The interrupt counter reaches the INTERRUPT_COUNT value, the PNX15xx
Series system reset is asserted.
The counters operate with the DCS clock also called MMIO clock (clk_dtl_mmio).
The following
Figure 3 pictures the events.
2.3 The Software Reset
The software reset is started by writing a 0x1 to RST.CTL.DO_SW_RST bit.
The reset follows then the regular software reset timing,
Section 3.2.2.4 The External Software Reset
The signal sys_rst_out_n signal can be asserted by writing a 0x1 to the
RST_CTL.ASSERT_SYS_RST_OUT bit.
The signal sys_rst_out_n signal can be de-asserted by writing a 0x1 to the
RST_CTL.REL_SYS_RST_OUT bit.
Figure 3:
Watchdog in Interrupt Mode
//
0
12
//
sys_rst_out_n
clk_dtl_mmio
watchdog_reset
peri_rst_n
SYS_RST_OUT_N
1
2
3
4
1: The interrupt is enabled then the watchdog count and the interrupt count registers are programmed.
2: The interrupt count is happening.
3: The interrupt count reaches the programmed value and a time out interrupt pulse is issued to the CPU.
FF
FE
0
//
12
0
60
//
time_out_int_pls
interrupt_count
watchdog_count
5
6
4: The watchdog counter begins.
5: The interrupt has not been cleared. A watchdog reset is issued.
6: The internal and external resets are asserted.