
Chapter 4
Registers
189
24674
Rev. 3.00
April 2003
AMD-8111 HyperTransport I/O Hub Data Sheet
AMD Preliminary Information
EIDE Controller Drive Timing Control Register
DevB:1x48
This register specifies timing for PIO data transfers (1F0h and 170h or the native mode equivalents)
and multi-word DMA transfers. The value in each 4-bit field, plus one, specifies a time in 30
nanosecond PCI clocks.
Notes:
1. For command and control transfers (1F1h-1F7h, 171h-177h, 3F6h and 376h) see
DevB:1x4C.
2. 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.
3. PIO modes are controlled through DevB:1x48 and DevB:1x4C. To set the timing associated
with the various modes, DevB:1x4C should be left at its default value and the appropriate
byte of DevB:1x48 should be programmed as follows—mode 0=A8h; mode 1=65h; mode
2=42h; mode 3=22h; mode 4=20h.
Default:
A8A8 A8A8h.
Attribute:
Read-write.
6:5
PHYSEL. PHY speed select.
Read-only. These specify the selected PHY speed selection as follows:
00b=bigger PHY resistor (fast corner); 10b=medium PHY resistor; x1b=smaller PHY resistor (slow
corner). The power-up default for these bits is device speci
fi
c.
Reserved. These bits are
fi
xed to 0.
PRIEN. Primary channel enable.
Read-write. 1=The primary port of the EIDE controller is enabled.
SECEN. Secondary channel enable.
Read-write. 1=The secondary port of the EIDE controller is
enabled.
4:2
1
0
Bits
31:28
PD0PW[3:0]. Primary drive 0 data DIOR_L/DIOW_L active pulse width
.
27:24
PD0RT[3:0]. Primary drive 0 data DIOR_L/DIOW_L minimum recovery time
.
23:20
PD1PW[3:0]. Primary drive 1 data DIOR_L/DIOW_L active pulse width
.
19:16
PD1RT[3:0]. Primary drive 1 data DIOR_L/DIOW_L minimum recovery time
.
15:12
SD0PW[3:0]. Secondary drive 0 data DIOR_L/DIOW_L active pulse width
.
11:8
SD0RT[3:0]. Secondary drive 0 data DIOR_L/DIOW_L minimum recovery time
.
7:4
SD1PW[3:0]. Secondary drive 1 data DIOR_L/DIOW_L active pulse width
.
3:0
SD1RT[3:0]. Secondary drive 1 data DIOR_L/DIOW_L minimum recovery time
.
Description
Bits
Description (Continued)