AMD-766AC AMD [Advanced Micro Devices], AMD-766AC Datasheet - Page 52

• Manufacturer Part Number: AMD-766AC
• Description: Peripheral Bus Controller
• Manufacturer: AMD [Advanced Micro Devices]

23167B – March 2001
C1A40: EIDE Controller Configuration Register
Configuration space; function 1; offset: 43-40h. Default: 0000 0400h.
31:24
Reserved
IDE_CONFIG[0] Secondary Channel Enable, SECEN. Read-write. 1=The secondary port of the EIDE controller
is enabled.
IDE_CONFIG[1] Primary Channel Enable, PRIEN. Read-write. 1=The primary port of the EIDE controller is
enabled.
IDE_CONFIG[4:2] MBLD. Must be left in their default state. Read-write. These bits are required to be left in their
default state; otherwise undefined behavior will result.
IDE_CONFIG[7:5] Reserved.
IDE_CONFIG[11:8] MBLD. Must be left in their default state. Read-write. These bits are required to be left in
their default state; otherwise undefined behavior will result.
IDE CONFIG[12] Secondary Posted Write Buffer, SECPWB. Read-write. 1=Enable the EIDE secondary port
PIO-mode posted-write buffer. Only 32-bit writes to the data port are allowed when this bit is set.
IDE CONFIG[13] Secondary Read Prefetch Buffer, SECRPB. Read-write. 1=Enable the EIDE secondary port
read-prefetch buffer.
IDE CONFIG[14] Primary Posted Write Buffer, PRIPWB. Read-write. 1=Enable the EIDE primary port PIO-
mode posted-write buffer. Only 32-bit writes to the data port are allowed when this bit is set.
IDE CONFIG[15] Primary Read Prefetch Buffer, PRIRPB. Read-write. 1=Enable the EIDE primary port read-
prefetch buffer.
CABLE. Read-write. These bits are expected to be programmed by BIOS to specify the cable type of each of the
IDE drives to the driver. 1=High speed 80-pin cable is present. The bits specify the drive as follows:
RW. Read-write. These bits are read-write accessible through software; they control no hardware.
C1A48: EIDE Controller Drive Timing Control
Configuration space; function 1; offset: 4B-48h. Default: A8A8 A8A8h. Read-write.
This register specifies timing for PIO data transfers (not 171h though 177h or 1F1h though 1F7h) and multi-word
DMA transfers. The value in each 4-bit field, plus one, specifies a time period in 30 nanosecond PCI clocks. Note:
The default state, A8h, results in a recovery time of 270ns and an active pulse width of 330ns for a 30ns PCI clock
(total cycle time = 600ns) which corresponds to ATA PIO Mode 0.
Note: PIO modes are controlled via C1A48 and C1A4C. To set the timing associated with the various modes,
C1A4C should be left at its default value and the appropriate byte of C1A48 should be programmed as follows: mode
0=A8h; mode 1=65h; mode 2=42h; mode 3=22h; mode 4=20h.
31:28
PD0PW
SD1RT[3:0] Secondary Drive 1 Minimum Recovery Time.
SD1PW[3:0] Secondary Drive 1 Active Pulse Width.
SD0RT[3:0] Secondary Drive 0 Minimum Recovery Time.
SD0PW[3:0] Secondary Drive 0 Active Pulse Width.
PD1RT[3:0] Primary Drive 1 Minimum Recovery Time.
PD1PW[3:0] Primary Drive 1 Active Pulse Width.
PD0RT[3:0] Primary Drive 0 Minimum Recovery Time.
PD0PW[3:0] Primary Drive 0 Active Pulse Width.
Bit[16]: primary master.
Bit[17]: primary slave.
Bit[18]: secondary master.
Bit[19]: secondary slave.
27:24
PD0RT
23:20
PD1PW
23:20
RW
19:16
PD1RT
19:16
CABLE
Preliminary Information
15:0
IDE_CONFIG
15:12
SD0PW
AMD-766
11:8
SD0RT
TM
Peripheral Bus Controller Data Sheet
7:4
SD1PW
3:0
SD1RT
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