PIC16LC63A-04 Datasheet, PDF (35/184 Pages) Microchip Technology – 8-Bit CMOS Microcontrollers with A/D Converter

PIC16C63A/65B/73B/74B
5.5 PORTE and TRISE Register
Note 1: The PIC16C63A and PIC16C73B do not
provide PORTE. The PORTE and TRISE
registers are not implemented.
2: The PIC16C63A/65B does not provide an
A/D module. A/D functions are not imple-
mented.
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
(PIC16C74B 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.
Note: On a Power-on Reset, these pins are con-
figured as analog inputs and read as ‘0’s.
FIGURE 5-7:
PORTE BLOCK DIAGRAM
Data
Bus
WR
Port
DQ
CK
I/O pin⁽¹⁾
Data Latch
WR
TRIS
DQ
CK
TRIS Latch
Schmitt
Trigger
Input
Buffer
RD Port
RD TRIS
Q
D
ENEN
Note 1: I/O pins have protection diodes to VDD and VSS.
TABLE 5-9: PORTE FUNCTIONS
Name
Bit#
Buffer Type Function
RE0/RD/AN5
RE1/WR/AN6
RE2/CS/AN7
bit0
ST/TTL⁽¹⁾
Input/output port pin or read control input in Parallel Slave Port mode or analog
input:
RD
1 = Idle
0 = Read operation. Contents of PORTD register is output to PORTD
I/O pins (if chip selected).
bit1
ST/TTL⁽¹⁾
Input/output port pin or write control input in Parallel Slave Port mode or analog
input:
WR
1 = Idle
0 = Write operation. Value of PORTD I/O pins is latched into PORTD
register (if chip selected).
bit2
ST/TTL⁽¹⁾
Input/output port pin or chip select control input in Parallel Slave Port mode or
analog input:
CS
1 = Device is not selected
0 = Device is selected
Legend: ST = Schmitt Trigger input, TTL = TTL input
Note 1: Input buffers are Schmitt Triggers when in I/O mode and TTL buffers when in Parallel Slave Port mode.
 2000 Microchip Technology Inc.
DS30605C-page 35