Fujitsu FR81S User Manual
CHAPTER 49: BUS DIAGNOSIS FUNCTION
1. Overview
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : BUS DIAGNOSIS FUNCTION
FUJITSU SEMICONDUCTOR CONFIDENTIAL
3
1. Overview
This section explains the overview of BUS diagnosis function.
The bus diagnosis function prevents an LSI malfunction by checking data that was output on a bus during
access to each resource.
Function
1
Diagnosis
target
⋅
Addresses and data to be output to the address and data buses, and control
signals (read, write, read-modify-write, and bus access size signals) for
controlling buses
2
Diagnosis bus ⋅ AHB, APB(PCLK2), Rbus(PCLK2), APB(PCLK1), Rbus(PCLK1)
3
Diagnosis
method
⋅
Diagnosis based on parity
The output side calculates parity for each 8-bit group and outputs that parity.
The input side checks that parity.
4
Parity
⋅
Odd parity
5
Test function ⋅ A parity error is generated to support program debug at bus diagnosis.
6
Error detection
⋅
Control parity error
⋅
Address parity error
⋅
Data parity error
At error occurrence, the relevant address is displayed in the register.
7
Effect
⋅
Detection of a bus disconnection
⋅
Detection of a bus transistor failure
⋅
Detection of garbled data resulting from a bus short caused by dirt
⋅
Detection of garbled data caused by a defective contact
8
NMI
notification
⋅
Control parity error, address parity error, data parity error
MB91520 Series
MN705-00010-1v0-E
2096