Fujitsu FR81S Manual Do Utilizador
CHAPTER 49: BUS DIAGNOSIS FUNCTION
2. Features
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : BUS DIAGNOSIS FUNCTION
FUJITSU SEMICONDUCTOR CONFIDENTIAL
4
2. Features
This section explains the features of BUS diagnosis function.
The internal bus of the CPU consists of AHB, APB(PCLK2), Rbus(PCLK2), APB(PCLK1) and
Rbus(PCLK1). The bus diagnosis function is accomplished by adding parity to AHB, APB, and Rbus address
and data, and to bus control signals and by checking that parity. However, if a parity error occurs at write
access to the bus diagnosis register, the NMI request signal cannot be cleared. So, the write access to bus
diagnosis register is excluded from diagnosis.
When the parity error is detected at write access, write access to peripheral resource is shut off.
NMI output resulting from bus diagnosis is generated by one of the following factors:
⋅
A control parity error (CNER) was detected.
⋅
A data parity error (DER[3:0]) was detected.
⋅
An address parity error (AER[3:0]) was detected.
MB91520 Series
MN705-00010-1v0-E
2097