Table 64 – Logical Device Registers
LOGICAL DEVICE
REGISTER
ADDRESS
(0x30)
DESCRIPTION
Bits[7:1] Reserved, set to zero.
STATE
ActivateNote1
C
Bit[0]
= 1
Default = 0x00
Activates the logical device currently
selected through the Logical Device #
register.
Logical device currently selected is
inactive
on VCC POR, VTR POR,
HARD RESET and
SOFT RESET
= 0
Logical Device Control
Logical Device Control
(0x31-0x37) Reserved – Writes are ignored, reads return 0.
C
C
(0x38-0x3f)
Vendor Defined - Reserved - Writes are
ignored, reads return 0.
Memory Base Address
I/O Base Address Note 2
(0x40-0x5F) Reserved – Writes are ignored, reads return 0.
(0x60-0x6F) Registers 0x60 and 0x61 set the base address
for the device. If more than one base address
C
C
(see Device Base I/O
Address Table)
0x60,2,... =
addr[15:8]
is required, the second base address is set by
registers 0x62 and 0x63.
Refer to Table 58 for the number of base
address registers used by each device.
Unused registers will ignore writes and return
zero when read.
Default = 0x00
0x61,3,... =
addr[7:0]
on VCC POR, VTR POR,
HARD RESET and
SOFT RESET
Interrupt Select
(0x70,0x72) 0x70 is implemented for each logical device.
Refer to Interrupt Configuration Register
description. Only the keyboard controller uses
Interrupt Select register 0x72. Unused register
(0x72) will ignore writes and return zero when
read. Interrupts default to edge high (ISA
compatible).
C
Defaults :
0x70 = 0x00 or 0x06
(Note 3)
on VCC POR, VTR POR,
HARD RESET and
SOFT RESET
0x72 = 0x00,
on VCC POR, VTR POR,
HARD RESET and
SOFT RESET
(0x71,0x73) Reserved - not implemented. These register
locations ignore writes and return zero when
read.
DMA Channel Select
(0x74,0x75) Only 0x74 is implemented for FDC and Parallel
port. 0x75 is not implemented and ignores
writes and returns zero when read. Refer to
DMA Channel Configuration.
C
Default = 0x02 or 0x04
(Note 4)
on VCC POR, VTR POR,
HARD RESET and
SOFT RESET
32-Bit Memory Space
Configuration
(0x76-0xA8) Reserved - not implemented. These register
locations ignore writes and return zero when
read.
Logical Device
(0xA9-0xDF) Reserved - not implemented. These register
locations ignore writes and return zero when
read.
C
C
C
Logical Device
Configuration
(0xE0-0xFE) Reserved
defined
–
Vendor Defined (see SMSC
Logical Device Configuration
Registers).
Reserved
0xFF
Reserved
Note 1: A logical device will be active and powered up according to the following equation:
Page 150
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