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Notes
79RC32438 User Reference Manual
4 - 1
November 4, 2002
Chapter 4
System Integrity Functions
Introduction
This chapter describes the system integrity functions on the RC32438. The system integrity module
includes several registers that log system activity. These registers can be used to indicate the source of
hardware or software errors.
Features
Programmable bus transaction timer generates warm reset when counter expires
Address space monitor
Programmable watchdog timer generates NMI when counter expires
Functional Overview
The RC32438 supports three functions to monitor activity within the system and report potential hard-
ware or software error conditions.
The first function is the bus transaction timer. The bus transaction timer times memory and peripheral
bus transactions, generating a warm reset if a transaction does not complete within a specified number of
clock cycles. The bus transaction timer is part of the device controller. For more information on the bus
transaction timer, see the Memory and Peripheral Bus Transaction Timer section in Chapter 6.
A second function is the address space monitor. The address space monitor generates an error in
response to bus transactions with invalid RC32438 local address space addresses. This applies to transac-
tions generated by the CPU as well as the PCI and DMA controllers.
A third function is the watchdog timer. The watchdog timer is a general purpose timer that, if not periodi-
cally reset by software, generates a nonmaskable interrupt (NMI) exception to the CPU or a warm reset.
The watchdog timer is independent from the three general purpose timers described in Chapter 14, Counter
Timers.
System integrity functions are controlled, and their status is reported in the Error Control and Status
(ERRCS) Register. The bus transaction timer, the address space monitor, and the watchdog are all enabled
following a cold reset. The bus timer and watchdog timer can be individually disabled by software.
The address of an undecoded CPU read/write operation or IPBus slave acknowledge error is recorded
in the CPU Error Address (CEA) register. This register is only accessible by the CPU since it is located in
the CPU BIU.
System Integrity Register Description
Register Offset
1
Register Name
Register Function
Size
0x03_0000 through 0x03_002C
Reserved
0x03_0030
ERRCS
Error control and status
32-bit
0x03_0034
WTCOUNT
Watchdog timer count
32-bit
Table 4.1 System Integrity Register Map (Part 1 of 2)