Z86E3016PSG Datasheet, PDF (117/348 Pages) Zilog, Inc. – Z86E3016PSG

Z8 CPU
User Manual
99
may output the comparator outputs by software-programming the PCON
Register bit D0 to 1.
Comparator Description
Two on-board comparators can process analog signals on P31 and P32
with reference to the voltage on P33. The analog function is enabled by
programming the Port 3 Mode Register (P3M bit 1). For interrupt func-
tions during analog mode, P31 and P32 can be programmable as rising,
falling, or both edge triggered interrupts (IRQ register bits 6 and bit 7).
P33 cannot generate an external interrupt while in this mode. P33 can only
generate interrupts in digital mode.
Port 3 inputs must be in digital mode if Port 3 is a Stop-Mode Recovery
source. The analog comparator is disabled in STOP mode.
P31 can be used as T_IN in analog or digital modes, but it must be refer-
enced to P33, when in analog mode.
Register F7h
Port 3 Mode Register (P3M)
(Write-Only)
D1
0 = Digital Mode P31, P32, P33
1 = Analog Mode P31, P32, P33
Figure 57. Port 3 Input Analog Selection
UM001602-0904
I/O Ports