Intel J1750 FH8065301562600 User Manual

Product codes
FH8065301562600
Page of 1272
PCU - iLB - 8259 Programmable Interrupt Controllers (PIC)
1268
Datasheet
31.3.9
SICW2—Offset A1h
Slave ICW2 is used to initialize the interrupt controller with the five most significant bits 
of the interrupt vector address. The value programmed for bits[7:3] is used by the CPU 
to define the base address in the interrupt vector table for the interrupt routines 
associated with each IRQ on the controller. Typical ISA ICW2 values are 08h for the 
master controller and 70h for the slave controller.
Access Method
Default: 00h
31.3.10
SOCW2—Offset A4h
Slave Operational Control Word 2 (Interrupt Mask).Following a part reset or ICW 
initialization, the controller enters the fully nested mode of operation. Non-specific EOI 
without rotation is the default. Both rotation mode and specific EOI mode are disabled 
following initialization.
Access Method
Default: 20h
Type: I/O Register
(Size: 8 bits)
SICW2: A1h
7
4
0
0
0
0
0
0
0
0
0
IVBA
IRL
Bit 
Range
Default & 
Access
Description
7:3
X
WO
IVBA: Interrupt Vector Base Address: Bits [7:3] define the base address in the interrupt 
vector table for the interrupt routines associated with each interrupt request level input.
2:0
X
WO
IRL: Interrupt Request Level: When writing ICW2, these bits should all be 0. During an 
interrupt acknowledge cycle, these bits are programmed by the interrupt controller with 
the interrupt to be serviced. This is combined with bits [7:3] to form the interrupt vector 
driven onto the data bus during the second INTA# cycle. The code is a three bit binary 
code: Code Master Interrupt Slave Interrupt 000 IRQ0 IRQ8 001 IRQ1 IRQ9 010 IRQ2 
IRQ10 011 IRQ3 IRQ11 100 IRQ4 IRQ12 101 IRQ5 IRQ13 110 IRQ6 IRQ14 111 IRQ7 
IRQ15
Type: I/O Register
(Size: 8 bits)
SOCW2: A4h
7
4
0
0
0
1
0
0
0
0
0
REOI
OC
W
2
S
ILS
Bit 
Range
Default & 
Access
Description
7:5
001b
WO
REOI: Rotate and EOI Codes: R, SL, EOI - These three bits control the Rotate and End 
of Interrupt modes and combinations of the two. A chart of these combinations is listed 
above under the bit definition. 000 - Rotate in Auto EOI Mode (Clear) 001 - Non-specific 
EOI command 010 - No Operation 011 - *Specific EOI Command 100 - Rotate in Auto 
EOI Mode (Set) 101 - Rotate on Non-Specific EOI Command 110 - *Set Priority 
Command 111 - *Rotate on Specific EOI Command *L0 - L2 Are Used