Acer Extensa 61X Service Manual page 125

Table 2-13 PCI1131 Pin Descriptions (Continued)
TERMINAL
Name Slot
Slot
A+ B
1 6-bit PC Card Address and Data (Slots A and B)
IORD 99 33
IOWR 101 35
OE 98 32
WAIT 136 70
WE 110 46
READY 135 69
(IREQ)
Terminal name is preceded with A_. As an example, the full name for terminal 121 is A_A25.
Terminal name is preceded with B_. As an example, the full name for terminal 55 is B_A25.
2-68
I/O
TYPE
O I/O Read. LORD is asserted by the PCI1131 to enable 16-bit l/O PC
Card data output during host I/O read cycles.
(DMA Write) This pin is used as the DMA write strobe during DMA
operations from a 16-bit PC Card which supports DMA. The PCI 1131
asserts this signal during DMA transfers from the PC Card to host
memory.
O I/O Write. IOWR is driven low by the PCI1131 to strobe write data into
16-bit l/O PC Cards during host I/O write cycles.
(DMA Read) This pin is used as the DMA read strobe during DMA
operations to a 16-bit PC Card which supports DMA. The PCI 1131
asserts this signal during DMA transfers from host memory to the PC
Card.
O Output Enable. OE is driven low by the PCI 1131 to enable 16-bit
Memory PC Card data output during host memory read cycles.
(DMA Terminal Count) This pin is used as TC during DMA operations to
a 16-bit PC Card which supports DMA. The PCI 1131 asserts this
signal to indicate Terminal Count for a DMA write operation .
I Bus Cycle Wait. WET is driven by a 16-bit PC Card to delay the
completion of (i e. extend) the memory or l/O cycle that is in progress.
O Write Enable . WE is used to strobe memory write data into 16-bit
Memory PC Cards. VVE is also used for memory PC Cards that employ
programmable memory technologies.
(DMA Terminal Count) This pin is used as TC during DMA operations to
a 16-bit PC Card which supports DMA. The PCI 1131 asserts this
signal to indicate Terminal Count for a DMA read operation.
Ready . The ready function is provided by the READY signal when the
I
16-bit PC Card and the host socket are configured for the memory-only
interface. READY is driven low by the 16-bit Memory
PC Cards to indicate that the memory card circuits are busy processing
a previous write command. READY is driven high when the 16-bit
Memory PC Card is ready to accept a new data transfer.
Interrupt Request. IREQ is asserted by a 16-bit I/O PC Card to indicate
to the host that a device on the 16-bit I/O PC Card requires service by
the host software. IREQ is high (deasserted) when no interrupt is
requested.
FUNCTION
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