Z86L88 Datasheet, PDF (24/66 Pages) Zilog, Inc. – INFRARED REMOTE CONTROLLERS

Z86L88/81/86/87/89/73
IR/Low-Voltage Microcontroller
PIN FUNCTIONS (Continued)
After the POR time, /RESET is a Schmitt-triggered input.
To avoid asynchronous and noisy reset problems, the
Z86LXX is equipped with a reset filter of four external
clocks (4TpC). If the external reset signal is less than 4TpC
in duration, no reset occurs. On the fifth clock after the re-
set is detected, an internal RST signal is latched and held
for an internal register count of 18 external clocks, or for
the duration of the external reset, whichever is longer.
During the reset cycle, /DS is held active Low while /AS cy-
cles at a rate of TpC/2. Program execution begins at loca-
tion 000CH, 5-10 TpC cycles after the RST is released. For
Power-On Reset, the typical reset output time is 5 ms. The
Z86LXX does not reset WDTMR, SMR, P2M, or P3M reg-
isters on a Stop-Mode Recovery operation. The output
states of Port3 and Port2 are also un-affected by a Stop-
Mode recovery.
P31 (AN1)
Pref
Z86L7X
MCU
Pref1
P31
P32
P33 _{Port 3}
(I/O or Handshake)
P34
P35
P36
P37
200 KΩ
Mask
Option
Note:
P31, 32, 33 have a 200 KΩ
mask option
R247 = P3M
D1
1 = Analog
0 = Digital
Comp1
+
-
DIG.
AN.
IRQ2, P31 Data Latch
P32 (AN2)
P33 (REF2)
Comp2
+
-
IRQ0, P32 Data Latch
From Stop-Mode
Recovery Source of SMR
IRQ1, P33 Data Latch
Figure 17. Port 3 Configuration
24
PRELIMINARY
DS96LV00800