PD6710 datasheet(84/138 Pages) INTEL

84 / 138 page

PD6710/’22 — ISA-to-PC-Card (PCMCIA) Controllers

Datasheet

11.0

Timing Registers

The following information about the timing registers is important:

• All timing registers take effect immediately and should only be changed when the FIFO is

empty (see the FIFO Control register on “FIFO Control” on page 72).

• Selection of Timing 0 or Timing 1 register sets is controlled by I/O Window Control, bit 3

and/or bit 7 (see “I/O Window Control” on page 58).

11.1

Setup Timing 0–1

There are two separate Setup Timing registers, each with identical fields. These registers are

located at the following indexes:

Index

Setup Timing

3Ah

Setup Timing 0

3Dh

Setup Timing 1

The Setup Timing register for each timing set controls how long a PC Card cycle’s command (that

is, -OE, -WE, -IORD, -IOWR; see Table 2 on page 20) setup will be, in terms of the number of

internal clock cycles.

The overall command setup number of clocks S is programmed by selecting a 2-bit prescaling

value (bits 7:6 of this register) representing weights of 1, 16, 256, or 8192, and then selecting a

multiplier value (bits 5:0) to which that prescalar is multiplied to produce the overall command

setup timing length according to the following formula:

S = (Npres × Nval) + 1

The value of S, representing the number of internal clock cycles for command setup, is then

multiplied by the internal clock’s period to determine the command setup time (see “PC Card Bus

Timing Calculations” on page 109 for further discussion).

Bits 5:0 — Setup Multiplier Value

This field indicates an integer value Nval from 0 to 63; it is combined with a prescalar value (bits

7:6) to control the length of setup time before a command becomes active.

Index: 3Ah, 3Dh

Bit 7Bit 6Bit 5Bit 4Bit 3Bit 2Bit 1Bit 0

Setup Prescalar Select

Setup Multiplier Value

RW:00

RW:000001

PD6710 Datasheet(PDF) 84 Page - Intel Corporation