Motorola MVME1X7P SCC Error Status and Interrupt Control Registers, SCC Error Status Register

Models: MVME1X7P

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Programming Model

SCC Error Status and Interrupt Control Registers

This section provides addresses and bit level descriptions of the SCC

interrupt control registers and status registers.

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SCC Error Status Register

ADR/SIZ

 

 

 

 

$FFF4201C (8 bits)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

BIT

31

30

 

29

 

28

27

 

26

25

24

 

 

 

 

 

 

 

 

 

 

 

 

NAME

 

 

 

 

 

RTRY

PRTY

 

EXT

LTO

SCLR

 

 

 

 

 

 

 

 

 

 

 

 

OPER

 

 

 

 

 

R

R

 

R

R

W/R-0

 

 

 

 

 

 

 

 

 

 

 

 

RESET

0

0

 

0

 

0 PL

0 PL

 

0 PL

0 PL

0

 

 

 

 

 

 

 

 

 

 

 

SCLR

 

Writing a 1 to this bit clears bits 25 through 28 (LTO,

 

 

 

EXT, PRTY, and RTRY). Reading this bit always yields

 

 

 

0.

 

 

 

 

 

 

 

LTO,EXT, These bits indicate the status of the last Local Bus PRTY,RTRY error condition encountered by the SCC while performing

DMA accesses to the Local Bus. A Local Bus error condition is flagged by the assertion of TEA*. When the SCC receives TEA* if the source of the error is local- time-out, then LTO is set and EXT, PRTY, and RTRY are cleared. If the source of the TEA* is due to an error in going to the VMEbus, then EXT is set and the other three status bits are cleared. If the source of the error is DRAM parity check error, then PRTY is set and the other three status bits are cleared. If the source of the TEA* is because a retry was needed, then RTRY is set and the other three status bits are cleared. If the source of the error is none of the above conditions, then all four bits are cleared. Writing a 1 to bit 24 (SCLR) also clears all four bits.

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Motorola MVME1X7P manual SCC Error Status and Interrupt Control Registers, SCC Error Status Register, Scl R