Intel 8253 - Page 686

6
A7
D7
A6
D6
A5
D5
1
D4
LTIM
D3
ADI
D2
SNGL
D1
IC4
D0
1 = ICW4 NEEDED
0 = NO ICW4 NEEDED
1 = SINGLE
0 = CASCADE MODE
CALL ADDRESS INTERVAL
1 = INTERVAL OF 4
0 = INTERVAL OF 8
1 = LEVEL TRIGGERED
0 = EDGE TRIGGERED
A7 - A5 OF INTERRUPT
VECTOR ADDRESS
(MCS-80/85 MODE ONLY)
0
A0
MODE
MODE
NOTE: Slave ID is equal to the corresponding master IR input.
FIGURE 5. 82C59A INITIALIZATION COMMAND WORD FORMAT
A15
D7
D6 D5 D4 D3
A10
D2
A9
D1
A8
D0
A15 - A8 OF INTERRUPT
1
A0
T7
VECTOR ADDRESS
(MCS80/85 MODE)
T7 - T3 OF INTERRUPT
VECTOR ADDRESS
(8086/8088 MODE)
A14
T6
A13
T5
A11
T3
A12
T4
S7
D7
S6
D6
S5
D5
S4
D4
S3
D3
S2
D2
S1
D1
S0
D0
1 = IR INPUT HAS A SLAVE
0
A0
0 = IR INPUT DOES NOT
HAVE A SLAVE
ICW3 (MASTER DEVICE)
ICW2
ICW1
0
D7
0
D6
0
D5
0
D4
0
D3
ID2
D2
ID1
D1
ID0
D0
SLAVE ID (NOTE)
1
A0
0
ICW3 (SLAVE DEVICE)
1 2 3 4 5 6 7
0 1010101
0
0110011
0
0001111
0
D7
0
D6
0
D5
SFNM
D4
BUF
D3
M/S
D2
AEOI
D1
µPM
D0
1 = 8086/8088 MODE
0 = MCS-80/85 MODE
1 = AUTO EOI
0 = NORMAL EOI
1
A0
ICW4
0 X
1
0
11
1 = SPECIAL FULLY
0 = NOT SPECIAL FULLY
NESTED MODE
NESTED MODE
- NON BUFFERED MODE
- BUFFERED MODE/SLAVE
- BUFFERED MODE/MASTER
FIGURE 6. 82C59A OPERATION COMMAND WORD FORMAT
M7
D7
M6
D6
M5
D5
M4
D4
M3
D3
M2
D2
M1
D1
M0
D0
1 = MASK SET
1
A0
0 = MASK RESET
INTERRUPT MASK
OCW1
R
D7
SL
D6
EOI
D5
0
D4
0
D3
L2
D2
L1
D1
L0
D0
0
A0
OCW2
IR LEVEL TO BE
0 1 2 3 4 5 6 7
0 1010101
0
0110011
0
0001111
ACTED UPON
0 1
0
1
11
NON-SPECIFIC EOI COMMAND
* SPECIFIC EOI COMMAND
ROTATE ON NON-SPECIFIC EOI COMMAND
ROTATE IN AUTOMATIC EOI MODE (SET)
ROTATE IN AUTOMATIC EOI MODE (CLEAR)
* ROTATE ON SPECIFIC EOI COMMAND
* SET PRIORITY COMMAND
0
1
0
10
00
11
0
0
1
101
001
END OF INTERRUPT
AUTOMATIC ROTATION
SPECIFIC ROTATION
* L0 - L2 are used.
0
D7
ESMM
D6
SMM
D5
0
D4
1
D3
P
D2
RR
D1
RIS
D0
1 = POLL COMMAND
0
A0
0
OCW3
1 0 1
0 01 1
IR REG
NO ACTION
ON NEXT
RD PULSE
IS REG
ON NEXT
RD PULSE
READ REGISTER COMMAND
0 = NO POLL COMMAND
0 1 0 1
0 01 1
RESET
NO ACTION
SPECIAL
MASK
SET
SPECIAL
MASK
SPECIAL MASK MODE
READ READ
NO OPERATION
Application Note 109