W83629D Ver la hoja de datos (PDF) - Winbond

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Fabricante

W83629D

PCI TO ISA BRIDGE SET

Winbond 

W83628F & W83629D

7.1.3 ISA Interface Signals

SYMBOL

SA[19:17]

SA[16:0]

SD[15:0]

AEN

IOR#

IOW#

PIN

98-96

94-83

81-77

110-

107,

104,

103,

101,

100,

8-15

118

120

121

I/O

OUT24t

I/O24t

I/O24t

OUT24t

I/O24t

I/O24t

FUNCTION

System Address Bus. These are the upper address lines that

define the ISA’s byte granular address space (up to 1 Mbyte).

SA[19:17] are at an unknown state upon PCIRST#.

System Address Bus. These are the bi-directional lower

address lines that define the ISA’s byte granular address space

(up to 1 Mbyte). SA[16:0] are at an unknown state upon

PCIRST#.

System Data. SD[15:0] provide the 16-bit data path for devices

residing on the ISA Bus. The W83628F tri-states SD[15:0] during

PCIRST#.

Address Enable. AEN is asserted during DMA cycles. This

signal is also driven high during W83628F initiated refresh

cycles. AEN is driven low upon PCIRST#.

I/O Read. IOR# is the command to an ISA I/O slave device that

the slave may drive data on to the ISA data bus (SD[15:0]).

I/O Write. IOW# is the command to an ISA I/O slave device that

the slave may latch data from the ISA data bus (SD[15:0]).

IOCHRDY

SYSCLK

RSTDRV

I/O Channel Ready. Resources on the ISA Bus negate

116 I/O24t IOCHRDY to indicate that additional time (wait states) is required

to complete the cycle.

99

OUT24t

ISA System Clock. SYSCLK is the reference clock for the ISA

bus. The SYSCLK is generated by dividing PCICLK by 3 or 4.

Reset Drive. W83628F asserts RSTDRV to reset devices that

74 OUT24t reside on the ISA Bus. The W83628F asserts this signal while

the PCIRST# is asserted.

IOCS16#

SBHE#

IOCHK#

124

INt

16-bit I/O Chip Select. This signal is driven by I/O devices on

the ISA Bus to indicate that they support 16-bit I/O bus cycles.

System Byte High Enable. SBHE# asserted indicates that a

18 I/O24t byte is being transferred on the upper byte (SD[15:8]) of the data

bus. SBHE# is at an unknown state upon PCIRST#.

105

INt

I/O Channel Check. IOCHK# can be driven by any resource on

the ISA bus during on detection of an error.

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