Z86L82 Datasheet, PDF (24/80 Pages) Maxim Integrated Products – 28-Pin Low-Voltage IR Microcontrollers

Z86L82/85/88
28-Pin Low-Voltage IR Microcontrollers
17
programming the Port 3 Mode Register (bit 1). P31 and P32 are programmable as
rising, falling, or both edge-triggered interrupts (IRQ register bits 6 and 7). Pref1
and P33 are the comparator reference voltage inputs. Access to the counter/timer
edge-detection circuit is through P31 or P20 (see “Common Control Register to
Counter/Timer T8 and T16” on page 39). Other edge-detect and IRQ modes are
described in Table 8.
Table 8. Pin Assignments
Pin
Pref1
P31
P32
P33
P34
P35
P36
P37
P20
I/O
IN
IN
IN
OUT
OUT
OUT
OUT
I/O
C/T
IN
T8
T16
T8/16
IN
Comp.
RF1
AN1
AN2
RF2
AO1
AO2
Int.
IRQ2
IRQ0
IRQ1
Port 3 also provides output for the counter/timers and the AND/OR logic. Control
is performed by programming bits D5–D4 of CTR1, bit 0 of CTR0, and bit 0 of
CTR2.
Comparator Inputs
In analog mode, P31 and P32 have a comparator front end. The comparator refer-
ence is supplied to Pref1 and P33. In this mode, the P33 internal data latch and its
corresponding IRQ1 are diverted to the SMR sources (excluding P31, P32, and
P33) as indicated in Figure 8 on page 16. In digital mode, P33 is used as D3 of
the Port 3 input register, which then generates IRQ1.
Note: Comparators are powered down by entering STOP Mode. For
P31–P33 to be used in a Stop-Mode Recovery source, these
inputs must be placed into digital mode.
Comparator Outputs
These outputs can be programmed to be output on P34 and P37 through the
PCON register. See Figure 9.
PS009007-1202