W78E54-16 Winbond, W78E54-16 Datasheet - Page 10

• Manufacturer Part Number: W78E54-16
• Description: 8-BIT MICROCONTROLLER
• Manufacturer: Winbond

PX3: External interrupt 3 priority high if set
EX3: External interrupt 3 enable if set
IE3: If IT3 = 1, IE3 is set/cleared automatically by hardware when interrupt is detected/serviced
IT3: External interrupt 3 is falling-edge/low-level triggered when this bit is set/cleared by software
PX2: External interrupt 2 priority high if set
EX2: External interrupt 2 enable if set
IE2: If IT2 = 1, IE2 is set/cleared automatically by hardware when interrupt is detected/serviced
IT2: External interrupt 2 is falling-edge/low-level triggered when this bit is set/cleared by software
Eight-source interrupt informations:
2. PORT4
Another bit-addressable port P4 is also available and only 4 bits (P4<3:0>) can be used. This port
address is located at 0D8H with the same function as that of port P1, except the P4.3 and P4.2 are
alternative function pins. It can be used as general I/O pins or external interrupt input sources ( INT2 ,
Example:
3. Reduce EMI Emission
Because of the large on-chip flash EEPROM, when a program is running in internal ROM space, the
ALE will be unused. The transition of ALE will cause noise, so it can be turned off to reduce the EMI
emission if it is useless. Turning off the ALE signal transition only requires setting the bit 0 of the
INT3 ).
External Interrupt 0
Timer/Counter 0
External Interrupt 1
Timer/Counter 1
Serial Port
Timer/Counter 2
External Interrupt 2
External Interrupt 3
INTERRUPT
SOURCE
P4
MOV
MOV
SETB
CLR
REG
P4, #0AH
A, P4
P4.0
P4.1
0D8H
ADDRESS
VECTOR
0BH
1BH
2BH
3BH
03H
13H
23H
33H
; Output data "A" through P4.0 P4.3.
; Read P4 status to Accumulator.
; Set bit P4.0
; Clear bit P4.1
SEQUENCE WITHIN
0 (highest)
1
2
3
4
5
6
7 (lowest)
PRIORITY LEVEL
POLLING
- 10 -
IE.0
IE.1
IE.2
IE.3
IE.4
IE.5
XICON.2
XICON.6
REQUIRED
SETTINGS
ENABLE
EDGE/LEVEL
INTERRUPT
W78E54
XICON.0
XICON.3
TCON.0
TCON.2
TYPE
-
-
-
-