 2000 Microchip Technology Inc.

DS39504A-page 4-13

Section 4 Architecture

4

I

Analog

Analog High Voltage Reference input.

DR reference voltage output on devices with comparators.

I

Analog

Analog High Voltage Reference input.

Usually multiplexed onto an analog pin.

I

Analog

Analog Low Voltage Reference input.

Usually multiplexed onto an analog pin.

P

—

Ground reference for logic and I/O pins.

P

—

Positive supply for logic and I/O pins.

P

—

Programming voltage input

WR

I

TTL

Write control for parallel slave port (See CS and RD pins also).

WRL

O

—

System bus write low byte strobe

WRH

O

—

System bus write high byte strobe

Table 4-1:

I/O Descriptions (Continued)

Pin Name

Pin

Type

Buffer

Type

Description

Legend: TTL = TTL-compatible input

CMOS = CMOS compatible input or output

ST = Schmitt Trigger input with CMOS levels

O = output

PU = Weak internal pull-up

I = input

Analog = Analog input or output

P = Power