Motorola MVME1X7P User Manual

Page 270

Advertising
background image

4-22

Computer Group Literature Center Web Site

MCECC Functions

4

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:

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

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

Advertising