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CHAPTER 4 INTERFACES
76
(2/2)
Offset
18H
1CH
20H
24H
28H
2CH
Name
Bit(s)
31 – 0
R/W
R
Default
all 0
Description
Reserved
Reserved
31 - 0
R
all 0
Subsystem ID
31 - 16
R
0000H
Subsystem ID. Can be loaded from an external serial
EEPROM.
Subsystem vendor ID. Can be loaded from an external
serial EEPROM.
Base address. Specifies the base address of the
64K-byte expansion ROM.
Reserved
Address Decode Enable. Enables access to the
expansion ROM.
0: Disable (initial value), 1: Enable
Subsystem
Vendor ID
Expansion ROM
Base Address
15 - 0
R
0000H
31 - 16
R/W
0000H
15 - 1
0
R
all 0
0
30H
R/W
34H
38H
3CH
Reserved
31 - 0
R
all 0
MAX_LAT
MIN_GNT
Interrupt Pin
Interrupt Line
31 - 24
23 - 16
15 - 8
7 - 0
R
R
R
00H
00H
01H
00H
Sets the value of the latency timer. Can be loaded from
an external serial EEPROM.
Specifies an interrupt pin using INTA#.
Specifies the interrupt line of the interrupt controller
connected to
μ
PD98405 interrupt signals.
R/W
Reserved
Retry Timer
31 - 16
15 - 8
R
all 0
00H
R/W
Specifies the maximum retry count for the
μ
PD98405.
After a reset, a value of 00H is loaded as the initial value
and the timer is disabled. To enable the timer, set a value
other than 0. If no response is returned after the specified
number of retries while the timer is enabled, the
μ
PD98405 sets the FERR bit of the GSR register and
stops the operation until it is reset.
Specifies the maximum number of clocks in which the
μ
PD98405 waits for TRDY_B. After a reset, a value of
00H is loaded as the initial value and the timer is disabled.
To enable the timer, set a value other than 0. If no
response is made while the
μ
PD98405 is waiting for
TRDY_B in the specified number of clocks while the timer
is enabled, the
μ
PD98405 sets the FERR bit of the GSR
register and stops the operation until it is reset.
40H
TRDY Timer
7 - 0
R/W
00H
When the
μ
PD98405 recognizes that a serial EEPROM is connected, the Subsystem Vendor ID, Subsystem
ID, and MIN_GNT/MAX_LAT fields of the configuration register are loaded from the external serial EEPROM
after power-on.