Memory and PCMCIA Control Module

 

 

 

Bit

Name

Description

 

 

 

12..8

RDNx<4:0>

ROM delay next access.

 

 

Number of memory clock cycles (minus 1) from address to data valid for subsequent

 

 

accesses of a burst ROM.

 

 

For Flash and SRAM, this determines the write pulse width.

 

 

One memory clock cycle is added to this value.

 

 

 

15..13

RRRx<2:0>

ROM/SRAM recovery time.

 

 

Number of memory clock cycles (divided by 2) from chip select deasserted after a

 

 

read to next chip select (of a different memory bank) or nRAS asserted. nCS

 

 

negated to nRAS asserted is 2*RRR or 1 cycle (whichever is greater).

 

 

For Flash and SRAM, this field will also be used after writes to hold off subsequent

 

 

accesses.

 

 

This field should be programmed with the maximum of Toff, write pulse high time

 

 

(Flash/SRAM), and write recovery before read (Flash).

 

 

 

1When SMCNFGx:RT=01, accesses to the selected bank will output a byte mask on nCAS<3:0> for both reads and writes. This option should be selected only when there is no DRAM in the system.

SA-1100 Developer’s Manual

10-11

Page 125
Image 125
Intel SA-1100 manual RDNx40 ROM delay next access, Accesses of a burst ROM