4

MCECC Functions

STOFF2

STOFF1

STOFF0

Scrubber Time Off

 

 

 

 

0

0

0

Request DRAM immediately

 

 

 

 

0

0

1

Request DRAM after 16 BCLK cycles

 

 

 

 

0

1

0

Request DRAM after 32 BCLK cycles

 

 

 

 

0

1

1

Request DRAM after 64 BCLK cycles

 

 

 

 

1

0

0

Request DRAM after 128 BCLK cycles

 

 

 

 

1

0

1

Request DRAM after 256 BCLK cycles

 

 

 

 

1

1

0

Request DRAM after 512 BCLK cycles

 

 

 

 

1

1

1

Request DRAM never

 

 

 

 

STON2-STON0

STON2-STON0 control the amount of time that the scrubber occupies the DRAM before providing a window during which the local bus and refresher might use it. They control the on time as follows:

STON2

STON1

STON0

Scrubber Time On

 

 

 

 

0

0

0

Keep DRAM for 1 memory cycle

 

 

 

 

0

0

1

Keep DRAM for 16 BCLK cycles

 

 

 

 

0

1

0

Keep DRAM for 32 BCLK cycles

 

 

 

 

0

1

1

Keep DRAM for 64 BCLK cycles

 

 

 

 

1

0

0

Keep DRAM for 128 BCLK cycles

 

 

 

 

1

0

1

Keep DRAM for 256 BCLK cycles

 

 

 

 

1

1

0

Keep DRAM for 512 BCLK cycles

 

 

 

 

1

1

1

Keep DRAM for TOTAL SCRUB TIME

 

 

 

 

4-22

Computer Group Literature Center Web Site

Page 270
Image 270
Motorola MVME1X7P manual STON2-STON0, Scrubber Time Off, Scrubber Time On