PIC16F193X Datasheet, PDF (101/418 Pages) Microchip Technology – 28/40/44-Pin Flash-Based, 8-Bit CMOS Microcontrollers with LCD Driver and nanoWatt Technology

6.6 PORTE and TRISE Registers
PORTE⁽¹⁾ is a 4-bit wide, bidirectional port. The
corresponding data direction register is TRISE. Setting a
TRISE bit (= 1) will make the corresponding PORTE pin
an input (i.e., put the corresponding output driver in a
High-Impedance mode). Clearing a TRISE bit (= 0) will
make the corresponding PORTE pin an output (i.e.,
enable the output driver and put the contents of the
output latch on the selected pin). The exception is RE3,
which is input only and its TRIS bit will always read as
‘1’. Example 6-5 shows how to initialize PORTE.
Reading the PORTE register (Register 6-18) reads the
status of the pins, whereas writing to it will write to the
PORT latch. All write operations are read-modify-write
operations. Therefore, a write to a port implies that the
PIC16F193X/LF193X
port pins are read, this value is modified and then
written to the PORT data latch. RE3 reads ‘0’ when
MCLRE = 1.
Note 1: RE<2:0> and TRISE<2:0> pins are
available on PIC16F1936 and
PIC16F1938 only.
EXAMPLE 6-5: INITIALIZING PORTE
BANKSEL PORTE
CLRF PORTE
BANKSEL ANSELE
CLRF ANSELE
BANKSEL TRISE
MOVLW B‘00001100’
MOVWF TRISE
;
;Init PORTE
;
;digital I/O
;
;Set RE<3:2> as inputs
;and set RE<1:0>
;as outputs
REGISTER 6-18: PORTE: PORTE REGISTER
U-0
—
bit 7
U-0
U-0
U-0
—
—
—
R-x/u
RE3
R/W-x/u
RE2⁽¹⁾
R/W-x/u
RE1⁽¹⁾
R/W-x/u
RE0⁽¹⁾
bit 0
Legend:
R = Readable bit
u = bit is unchanged
‘1’ = Bit is set
W = Writable bit
x = Bit is unknown
‘0’ = Bit is cleared
U = Unimplemented bit, read as ‘0’
-n/n = Value at POR and BOR/Value at all other Resets
bit 7-4
bit 3-0
Unimplemented: Read as ‘0’
RE<3:0>: PORTE I/O Pin bits⁽¹⁾
1 = Port pin is > VIH
0 = Port pin is < VIL
Note 1: RE<2:0> are not implemented on the PIC16F1933/1936/1938. Read as ‘0’.
REGISTER 6-19: LATE: PORTE DATA LATCH REGISTER
U-0
—
bit 7
U-0
U-0
U-0
R/W-x/u
—
—
—
LATE3
R/W-x/u
LATE2
R/W-x/u
LATE1
R/W-x/u
LATE0
bit 0
Legend:
R = Readable bit
u = bit is unchanged
‘1’ = Bit is set
W = Writable bit
x = Bit is unknown
‘0’ = Bit is cleared
U = Unimplemented bit, read as ‘0’
-n/n = Value at POR and BOR/Value at all other Resets
bit 7-4
bit 3-0
Unimplemented: Read as ‘0’
LATE<3:0>: PORTE Output Latch Value bits⁽¹⁾
Note 1: Writes to PORTE are actually written to corresponding LATE register. Reads from PORTE register is
return of actual I/O pin values.
© 2008 Microchip Technology Inc.
Preliminary
DS41364A-page 99