Chip Prescaler Counter; Scrub Time On/Time Off Register - Motorola MVME172 Programmer's Reference Manual

Chip Prescaler Counter

This register reflects the current value in the prescaler counter. The
Prescaler Counter is used with the BCLK Frequency Register to produce a
1 MHz clock signal for use by the refresher, and by the scrubber. The
register is readable and writable for test purposes. Programming of this
register is not recommended.
ADR/SIZ
BIT
31
NAME
CPS7
OPER R/W
RESET
0 P

Scrub Time On/Time Off Register

ADR/SIZ
BIT
31
NAME SRDIS
OPER
R/W
RESET
0 PLS
STOFF2-STOFF0
http://www.mcg.mot.com/literature
1st $FFF43030/2nd $FFF43130 (8-bits)
30 29 28
CPS6 CPS57 CPS4
R/W R/W R/W
0 P 0 P 0 P
1st $FFF43034/2nd $FFF43134 (8-bits)
30 29 28
0 STON2 STON1
R R/W R/W
0 0 PLS 0 PLS
STOFF2-STOFF0 control the amount of time that the
scrubber refrains from requesting use of the DRAM each
time it gives it up during a scrub. They control the off time
as follows:
Programming Model
27 26
CPS3 CPS2
R/W R/W
0 P 0 P
27 26 25
STON0 STOFF2 STOFF1
R/W R/W R/W
0 PLS 0 PLS 0 PLS
25 24
CPS1 CPS0
R/W R/W
0 P 0 P
24
STOFF0
R/W
0 PLS
5-25
5