W83787IF Datasheet, PDF (4/123 Pages) Winbond – WINBOND I/O WITH SERIAL-INFRARED SUPPORT

W83787IF
Host Interface, continued
SYMBOL PIN I/O
AEN
62 I
IOR
IOW
DRQ2
63 I
64 I
100 O
DACK2 ^{98 I}
TC
97 I
IRQ6
IRQ4
99 O
37 O
IRQ3
44 O
IRQ7
23 O
PDRQX
4 I/O
HPRTM1
PRTOE ^{18 I}
PDACKX
XTAL1
XTAL2
7I
8O
FUNCTION
System address bus enable
CPU I/O read signal
CPU I/O write signal
When DRQ2 = 1, a DMA request is being made by the FDC
DMA Acknowledge. When this pin is active, a DMA cycle is underway
and the controller is executing a DMA transfer.
Terminal Count. When active, this pin indicates termination of a DMA
transfer.
Interrupt request generated by FDC
Interrupt request generated by UART A or UART B when their addresses
are COM1 or COM3.
This interrupt request can be tri-stated by setting bit 3 of HCR low.
This signal is at high impedance after each reset operation.
Interrupt request generated by UART A or UART B when their addresses
are COM2 or COM4.
Same as IRQ4
When IRQ7 = 1 and interrupt request is being made by the printer, this
pin is pulled high internally.
In EPP or ECP mode, IRQ7 is pulsed low, then released to allow sharing
of interrupts.
In Extension Adapter mode this pin is a DMA Request generated by
Extension Adapter. This request is output directly from XDRQ.
In ECP mode, this pin is the parallel port DMA Request output.
During power-on reset, this pin is pulled down internally and is defined as
HPRTM1, which is used for selecting the mode of the parallel port (see
Table 1-1).
In printer mode, this pin is for data direction control. When it is set to low,
the parallel port functions as an output port. When it is set to high, the
direction of the data bus is controlled by Bit 5 (DIR) of the printer control
register and Bit 7 (PRTBEN) of CR3. This pin is pulled up internally.
In Extension Adapter mode, this pin is the DMA acknowledge for the
Extension Adapter. When this pin is active, a DMA cycle is underway
and the controller is executing a DMA transfer.
In ECP mode, this pin is the parallel port DMA Acknowledge input.
24Mhz XTAL/Oscillator/Clock input
XTAL output
Publication Release Date:Sep 1995
-4-
Revision A1