W83787IF Datasheet, PDF (62/123 Pages) Winbond – WINBOND I/O WITH SERIAL-INFRARED SUPPORT

W83787IF
PRTMOD1 PRTMOD0 (Bit 3, Bit 2):
These two bits and PRTMOD2 (CR9 bit7) determine the parallel port mode of the W83787IF (see
Table 7-1 on next page ).
Table 7-1
PRTMODS2
(BIT 7 OF CR9)
0
0
0
0
1
1
1
1
PRTMOD1
(BIT 3 OF CR0)
0
0
1
1
0
0
1
1
PRTMODS0
(BIT 2 OF CR0)
0
1
0
1
0
1
0
1
W83757
EXTFDC
EXTADP
EXT2FDD
JOYSTICK
EPP/SPP
ECP
ECP/EPP
00 W83757 Mode (Default), PRTMOD2 = 0
Default state after power-on reset. In this mode, the W83787IF is fully compatible
with the W83757F/W83757AF.
01 Extension FDD Mode (EXTFDD), PRTMOD2 = 0
10 Extension Adapter Mode (EXTADP), PRTMOD2 = 0
11 Extension 2FDD Mode (EXT2FDD), PRTMOD2 = 0
00 JOYSTICK Mode, PRTMOD2 = 1
01 EPP Mode and SPP Mode, PRTMOD2 = 1
10 ECP Mode, PRTMOD2 = 1
11 ECP Mode and EPP Mode, PRTMOD2 = 1
OSCS1, OSCS0 (Bit 1, Bit 0):
These two bits and OSCS2 (CR6 bit 6) are used to select one of the W83787IF's power-down
functions. These bits may be programmed in four different ways:
00 Default power-on state after power-on reset (OSCS2 = 0).
00 OSC on, 24 MHz clock is stopped internally (OSCS2 = 1). Clock can be restarted by
clearing OSCS2.
01 Immediate power-down (IPD) state, OSCS2 = 0
When bit 0 is 1 and bit 1 is set to 0, the W83787IF will stop its oscillator and enter power-down mode
immediately. The W83787IF will not leave the power-down mode until either a system power-on reset
from the MR pin or these two bits are used to program the chip back to power-on state. After leaving
the power-down mode, the W83787IF must wait 128 mS for the oscillator to stabilize.
10 Standby for automatic power-down (APD), OSCS2 = 0
When bit 1 is set to 1 and bit 0 is set to 0, the W83787IF will stand by for automatic
power-down. A power-down will occur when the following conditions obtain:
• FDC not busy
• FDD motor off
• Interrupt source of line status, modem status, and data ready is inactive (neglecting IER
enable/disable)
• Master Reset inactive
• SOUTA and SOUTB in idle state
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Publication ReleaseDate:Sep 1995
Revision A1