z86d73 ZiLOG Semiconductor, z86d73 Datasheet - Page 61

• Manufacturer Part Number: z86d73
• Description: 40/44/48-pin Low-voltage
• Manufacturer: ZiLOG Semiconductor

PS019402-1103
Table 15. Interrupt Types, Sources, and Vectors
When more than one interrupt is pending, priorities are resolved by a programma-
ble priority encoder controlled by the Interrupt Priority Register. An interrupt
machine cycle is activated when an interrupt request is granted. As a result, all
subsequent interrupts are disabled, and the Program Counter and Status Flags
are saved. The cycle then branches to the program memory vector location
reserved for that interrupt. All Z86D73 interrupts are vectored through locations in
the program memory. This memory location and the next byte contain the 16-bit
address of the interrupt service routine for that particular interrupt request. To
accommodate polled interrupt systems, interrupt inputs are masked, and the Inter-
rupt Request register is polled to determine which of the interrupt requests require
service.
An interrupt resulting from AN1 is mapped into IRQ2, and an interrupt from AN2 is
mapped into IRQ0. Interrupts IRQ2 and IRQ0 can be rising, falling, or both edge
triggered. These interrupts are programmable by the user. The software can poll
to identify the state of the pin.
Programming bits for the Interrupt Edge Select are located in the IRQ Register
(R250), bits D7 and D6. The configuration is indicated in Table 16.
Table 16. IRQ Register*
Name
IRQ0
IRQ1
IRQ2
IRQ3
IRQ4
IRQ5
Notes: F = Falling Edge; R = Rising Edge
*
In stop mode, the comparators are turned off.
D7
0
0
1
1
Source
P32
P33
P31, T
T16
T8
LVD
IRQ
IN
D6
0
1
0
1
P
Vector Location
0,1
2,3
4,5
6,7
8,9
10,11
R
E
IRQ2 (P31)
L
R/F
R
F
F
Interrupt Edge
I
M
Comments
External (P32), Rising Falling Edge Triggered
External (P33), Falling Edge Triggered
External (P31), Rising Falling Edge Triggered
Internal
Internal
Internal
I
IRQ0 (P32)
N
R/F
R
F
F
A
40/44/48-Pin Low-Voltage IR OTP
R
Y
Z86D73
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