Datasheet

 1996 Microchip Technology Inc. DS30412C-page 13
PIC17C4X
PORTD is a bi-directional I/O Port.
RD0/AD8 40 43 15 I/O TTL This is also the upper byte of the 16-bit system bus in
microprocessor mode or extended microprocessor mode
or extended microcontroller mode. In multiplexed system
bus configuration these pins are address output as well
as data input or output.
RD1/AD9 39 42 14 I/O TTL
RD2/AD10 38 41 13 I/O TTL
RD3/AD11 37 40 12 I/O TTL
RD4/AD12 36 39 11 I/O TTL
RD5/AD13 35 38 10 I/O TTL
RD6/AD14 34 37 9 I/O TTL
RD7/AD15 33 36 8 I/O TTL
PORTE is a bi-directional I/O Port.
RE0/ALE 30 32 4 I/O TTL In microprocessor mode or extended microcontroller
mode, it is the Address Latch Enable (ALE) output.
Address should be latched on the falling edge of ALE
output.
RE1/OE
29 31 3 I/O TTL In microprocessor or extended microcontroller mode, it is
the Output Enable (OE
) control output (active low).
RE2/WR
28 30 2 I/O TTL In microprocessor or extended microcontroller mode, it is
the Write Enable (WR
) control output (active low).
TEST 27 29 1 I ST Test mode selection control input. Always tie to V
SS
for nor-
mal operation.
V
SS
10,
31
11,
12,
33, 34
5, 6,
27, 28
P Ground reference for logic and I/O pins.
V DD 1 1, 44 16, 17 P Positive supply for logic and I/O pins.
TABLE 3-1:
PINOUT DESCRIPTIONS
Name
DIP
No.
PLCC
No.
QFP
No.
I/O/P
Type
Buffer
Type
Description
Legend: I = Input only; O = Output only; I/O = Input/Output; P = Power; — = Not Used; TTL = TTL input;
ST = Schmitt Trigger input.