W83787IF Datasheet, PDF (49/123 Pages) Winbond – WINBOND I/O WITH SERIAL-INFRARED SUPPORT

W83787IF
an EPP data write cycle to be performed, and the trailing edge of IOW latches the data for the
duration of the EPP write cycle.
During a read operation, ports PD0-PD7 are read, and the leading edge of IOR causes an EPP read
cycle to be performed and the data to be output to the host CPU.
5.2.6 Bit Map of Parallel Port and EPP Registers
REGISTER
7
6
5
4
3
2
Data Port (R/W)
PD7 PD6 PD5 PD4 PD3 PD2
Status Buffer (Read)
BUSY ACK ^{PE SLCT} ERROR ¹
1
PD1
1
0
PD0
TMOUT
Control Swapper (Read) 1
1
1 IRQEN SLIN _{INIT AUTOFD STROBE}
Control Latch (Write)
1
1 DIR IRQ
SLIN _{INIT AUTOFD STROBE}
EPP Address Port
(R/W)
PD7 PD6 PD5 PD4 PD3 PD2 PD1
PD0
EPP Data Port 0 (R/W) PD7 PD6 PD5 PD4 PD3 PD2 PD1
PD0
EPP Data Port 1 (R/W) PD7 PD6 PD5 PD4 PD3 PD2 PD1
PD0
EPP Data Port 2 (R/W) PD7 PD6 PD5 PD4 PD3 PD2 PD1
PD0
EPP Data Port 3 (R/W) PD7 PD6 PD5 PD4 PD3 PD2 PD1
PD0
5.2.7 EPP Pin Descriptions
EPP
NAME
TYPE
EPP DESCRIPTION
nWrite
PD<0:7>
O Denotes an address or data read or write operation.
I/O Bi-directional EPP address and data bus.
Intr
nWait
PE
Select
nDStrb
nError
nInits
nAStrb
I Used by peripheral device to interrupt the host.
I Inactive to acknowledge that data transfer is completed. Active to indicate
that the device is ready for the next transfer.
I Paper end; same as SPP mode.
I Printer selected status; same as SPP mode.
O This signal is active low. It denotes a data read or write operation.
I Error; same as SPP mode.
O This signal is active low. When it is active, the EPP device is reset to its
initial operating mode,
O This signal is active low. It denotes an address read or write operation.
5.2.8 EPP Operation
When the EPP mode is selected in the configuration register, the standard and bi-directional modes
are also available. The PDx bus is in the standard or bi-directional mode when no EPP read, write, or
address cycle is currently being executed. In this condition all output signals are set by the SPP
Control Port and the direction is controlled by DIR of the Control Port.
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Publication ReleaseDate:Sep 1995
Revision A1