Programming Model

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

 

 

1st $FFF43030/2nd $FFF43130 (8-bits)

 

 

 

 

 

 

 

 

 

 

 

BIT

31

30

 

29

28

27

26

25

24

 

 

 

 

 

 

 

 

 

 

NAME

CPS7

CPS6

 

CPS57

CPS4

CPS3

CPS2

CPS1

CPS0

 

 

 

 

 

 

 

 

 

 

OPER

R/W

R/W

 

R/W

R/W

R/W

R/W

R/W

R/W

 

 

 

 

 

 

 

 

 

 

RESET

0 P

0 P

 

0 P

0 P

0 P

0 P

0 P

0 P

 

 

 

 

 

 

 

 

 

 

5

Scrub Time On/Time Off Register

ADR/SIZ

 

 

1st $FFF43034/2nd $FFF43134 (8-bits)

 

 

 

 

 

 

 

 

 

 

BIT

31

30

29

28

27

26

25

24

 

 

 

 

 

 

 

 

 

NAME

SRDIS

0

STON2

STON1

STON0

STOFF2

STOFF1

STOFF0

 

 

 

 

 

 

 

 

 

OPER

R/W

R

R/W

R/W

R/W

R/W

R/W

R/W

 

 

 

 

 

 

 

 

 

RESET

0 PLS

0

0 PLS

0 PLS

0 PLS

0 PLS

0 PLS

0 PLS

 

 

 

 

 

 

 

 

 

STOFF2-STOFF0

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:

http://www.mcg.mot.com/literature

5-25

Page 315
Image 315
Motorola MVME172 manual Chip Prescaler Counter, Scrub Time On/Time Off Register, STOFF2-STOFF0