Programming Model

Scrub Control Register

ADR/SIZ

 

1st $FFF43024/2nd $FFF43124 (8-bits)

 

 

 

 

 

 

 

 

 

 

 

 

BIT

31

30

29

28

27

26

 

25

24

 

 

 

 

 

 

 

 

 

 

NAME

RACODE

RADATA

HITDIS

SCRB

SCRBEN

0

 

SBEIEN

IDIS

 

 

 

 

 

 

 

 

 

 

OPER

R/W

R/W

R/W

R

R/W

R

 

R/W

R/W

 

 

 

 

 

 

 

 

 

 

RESET

V PLS

0 PLS

V PLS

0 PLS

0 PLS

X

 

0 PLS

0 PLS

 

 

 

 

 

 

 

 

 

 

IDIS When cleared, the Image DISable bit allows writes to the upper MCECC control registers to duplicate the data to the lower MCECC control registers. When IDIS is set, the lower MCECC control registers are written separately by the data on D00-D16. IDIS should only be set for test purposes.

SBEIEN Setting SBEIEN causes the logging of a single bit error to create a true pulse on the INT signal pin.

SCRBEN This control bit enables the scrubber to operate. When SCRBEN is set, the MCECC immediately performs a scrub of the entire DRAM array. When the scrub is complete, if software has cleared SCRBEN, then scrubbing is not done again, until software sets the SCRBEN bit. If software has not cleared the SCRBEN bit, then when the amount of time indicated in the Scrub Period (SBPD) Register expires, the MCECC scrubs the DRAM array again. It continues to perform scrubs of the entire DRAM array at the frequency indicated in the SBPD Register. The scrubber does not start a new scrub once the SCRBEN bit is cleared. The time between scrubs is approximately two seconds times the value stored in the SBPD Register. Note that power-up, local, or software reset stops the scrubber.

SCRB This status bit reflects the state of the scrubber. When the scrubber is in the process of doing a scrub, this bit is set. When the scrubber is between scrubs, this bit is cleared.

5

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Image 313
Motorola MVME172 manual Scrub Control Register