PD6710/’22 — ISA-to-PC-Card (PCMCIA) Controllers
Bits 5:0 — Command 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 that a command is active.
Bits 7:6 — Command Prescalar Select
00
01
10
11
N
N
N
N
= 1
pres
pres
pres
pres
= 16
= 256
= 8192
This field chooses one of four prescalar values Npres that are combined with the value of the
Command Multiplier Value (bits 5:0) to control the length that a command is active.
11.3
Recovery Timing 0–1
Register Name: Recovery Timing 0–1
Index: 3Ch, 3Fh
Register Per: socket
Register Compatibility Type: 365
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Recovery Prescalar Select
RW:00
Recovery Multiplier Value
RW:000011
There are two separate Recover Timing registers, each with identical fields. These registers are
located at the following indexes:
Index Recovery Timing
3Ch
3Fh
Recovery Timing 0
Recovery Timing 1
The Recovery 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) recovery will be, in terms of the
number of internal clock cycles.
The overall command recovery timing length R 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
recovery timing length according to the following formula:
R = (Npres × Nval) + 1
The value of R, representing the number of internal clock cycles for command recovery, is then
multiplied by the internal clock’s period to determine the command recovery time (see “PC Card
Bus Timing Calculations” on page 109 for further discussion).
86
Datasheet
INTEL [ INTEL ]
