Icu Registers - Intel 386 User Manual

Intel386™ EX EMBEDDED MICROPROCESSOR USER'S MANUAL
Expanded
Register
Address
P3CFG 0F824H
(read/write)
INTCFG 0F832H
(read/write)
ICW1 (master) 0F020H
ICW1 (slave) 0F0A0H
(write only)
ICW2 (master) 0F021H
ICW2 (slave) 0F0A1H
(write only)
ICW3 (master) 0F021H
(write only)
ICW3 (slave) 0F0A1H
(write only)
ICW4 (master) 0F021H
ICW4 (slave) 0F0A1H
(write only)
OCW1 (master) 0F021H
OCW1 (slave) 0F0A1H
(read/write)
OCW2 (master) 0F020H
OCW2 (slave) 0F0A0H
(write only)
OCW3 (master) 0F020H
OCW3 (slave) 0F0A0H
(write only)
NOTE: All master 82C59A registers are accessed through two expanded or PC/AT addresses; all the slave
registers are accessed through two other expanded or PC/AT addresses. The order in which you write
or read these addresses along with certain register bit settings determines which register is accessed.
9-16
Table 9-2. ICU Registers (Sheet 1 of 2)
PC/AT*
Address
— Port 3 Configuration:
The INT3:0 signals are multiplexed with P3.5:2. This register
determines which signals are connected to the package pins.
When a P3. n signal rather than an INT n signal is connected to
a package pin, V
— Interrupt Configuration:
Determines the master's and the slave's IR signal
connections: SIOINT1 or INT8; SIOINT0 or INT9; V
V or INT6; SSIOINT or INT5; V
SS
and INT6. Also enables the master's cascade bus (CAS2:0).
When enabled, the cascade signals appear on the A18:16
address lines during an interrupt acknowledge cycle.
0020H Initialization Command Word 1:
00A0H
Determines whether interrupt request signals are level
sensitive or edge triggered.
0021H Initialization Command Word 2:
00A1H
Contains the base interrupt vector number for the 82C59A.
The base interrupt vector is the IR0 vector number, the base
plus one is the IR1 vector number, and so on.
0021H Initialization Command Word 3:
Identifies the master's IR signals that are connected to slave
82C59A devices. The internal slave is connected to the
master's IR2 signal. You can connect external slaves to the
master's IR1, IR3, IR4, IR5, IR6, and IR7 signals.
00A1H Initialization Command Word 3:
Indicates that the internal slave is cascaded from the master's
IR2 signal.
0021H Initialization Command Word 4:
00A1H
Selects either special-fully nested or fully nested mode and
enables the automatic end-of-interrupt mode.
0021H Operation Command Word 1:
00A1H
Masks (disables) individual interrupt request signals.
0020H Operation Command Word 2:
00A0H
Changes interrupt levels and sends end-of-interrupt
commands.
0020H Operation Command Word 3:
00A0H
Enables special mask mode, issues the poll command, and
allows access to the interrupt request and in-service registers.
Function
is connected to the master's IR n signal.
SS
or INT4. Swaps DMAINT
SS
or INT7;
SS