Datasheet

PIC16C745/765
DS41124D-page 38 Preliminary  1999-2013 Microchip Technology Inc.
5.5 PORTE and TRISE Registers
PORTE has three pins, RE0/RD/AN5, RE1/WR/AN6
and RE2/CS
/AN7, which are individually configured as
inputs or outputs. These pins have Schmitt Trigger
input buffers.
I/O PORTE becomes control inputs for the micropro-
cessor port when bit PSPMODE (TRISE<4>) is set. In
this mode, the user must make sure that the
TRISE<2:0> bits are set (pins are configured as digital
inputs) and that register ADCON1 is configured for dig-
ital I/O. In this mode, the input buffers are TTL.
Register 5-1 shows the TRISE register, which also con-
trols the parallel slave port operation.
PORTE pins may be multiplexed with analog inputs
(PIC16C765 only). The operation of these pins is
selected by control bits in the ADCON1 register. When
selected as an analog input, these pins will read as '0's.
TRISE controls the direction of the RE pins, even when
they are being used as analog inputs. The user must
make sure to keep the pins configured as inputs when
using them as analog inputs.
TRISE bits are used to control the parallel slave port.
FIGURE 5-7: PORTE BLOCK DIAGRAM
TABLE 5-9: PORTE
(1)
FUNCTIONS
Note 1: The PIC16C745 does not provide
PORTE. The PORTE and TRISE registers
are reserved. Always maintain these bits
clear.
Note: On a Power-on Reset, these pins are con-
figured as analog inputs.
Data
Bus
WR
Port
WR
TRIS
RD Port
Data Latch
TRIS Latch
RD TRIS
Schmitt
Tr i gg e r
Input
Buffer
QD
CK
QD
CK
EN
QD
EN
I/O pin
To A/D Converter
VDD
Name Function
Input
Type
Output
Type
Description
RE0/RD
/AN5
RE0 ST CMOS Bi-directional I/O
(1)
RD TTL — Parallel Slave Port Control Input
(1)
AN5 AN — A/D Input
(1)
RE1/WR/AN6
RE1 ST CMOS Bi-directional I/O
(1)
WR TTL — Parallel Slave Port Control Input
(1)
AN6 AN — A/D Input
(1)
RE2/CS/AN7
RE2 ST CMOS Bi-directional I/O
(1)
CS TTL — Parallel Slave Port Data Input
(1)
AN7 AN — A/D Input
(1)
Legend: OD = open drain, ST = Schmitt Trigger
Note 1: PIC16C765 only.