L8253-5

General Description

The Z86L825/826/827 are ROM-based members of the Z8 MCU single-chip family of IR (infrared) with 237 bytes of general-purpose RAM and 4 KB of ROM. ZiLOG’s CMOS microcontrollers offer fast executing, efficient use of memory, sophisticated interrupts, input/output bit manipulation capabilities, automated pulse generation/reception, and internal key-scan pull-up transistors.

Features
• Low power consumption–60 mW (typical)
• Three standby modes
– STOP—2 µA
– HALT—0.8 mA
– Low voltage
• Special architecture to automate both generation and reception of complex
pulses or signals:
– One programmable 8-bit counter/timer with two capture registers and two
load registers
– One programmable 16-bit counter/timer with one 16-bit capture register
pair and one 16-bit load register pair
– Programmable input glitch filter for pulse reception
• Six priority interrupts
– Three external
– Two assigned to counter/timers
– One low battery voltage detection interrupt
• Low battery voltage detection with flag
• Programmable watch-dog/power-on reset circuits
• Two independent comparators with programmable interrupt polarity
• Mask selectable 200±50% KΩ transistor pull-ups on Ports 2 and 3. Port 0
always has pull-up selected.
– Programmable mask options:
– Oscillator selection: RC oscillator versus crystal or other clock source
– Oscillator operational mode: normal high-frequency operation enabled or
32-KHz operation enabled
– Port 2: 0–7 pull-ups
– Port 3: pull-ups
– Port 0: 0–3 Mouse Mode: Normal Mode(.5VDD input threshold) versus
Mouse Mode (.4VDD input threshold)