Datasheet

PIC16C9XX
DS30444E - page 38  1997 Microchip Technology Inc.
5.5 PORTE and TRISE Register
PORTE is an digital input only port. Each pin is multi-
plexed with an LCD segment driver. These pins have
Schmitt Trigger input buffers.
EXAMPLE 5-5: INITIALIZING PORTE
BCF STATUS,RP0 ;Select Bank2
BSF STATUS,RP1 ;
BCF LCDSE,SE27 ;Make all PORTE
BCF LCDSE,SE5 ;and PORTG<7>
BCF LCDSE,SE9 ;digital inputs
Note 1: On a Power-on Reset these pins are con-
figured as LCD segment drivers.
Note 2: To configure the pins as a digital port, the
corresponding bits in the LCDSE register
must be cleared. Any bit set in the LCDSE
register overrides any bit settings in the
corresponding TRIS register.
FIGURE 5-8: PORTE BLOCK DIAGRAM
RD PORT
Schmitt
Trigger
input
buffer
EN
Q D
EN
Digital Input/
LCDSE<n>
LCD
LCD Segment
LCD Output pin
LCD
LCD Common
Data Bus
RD TRIS
V
DD
Segment Data
Output Enable
Common Data
Output Enable
TABLE 5-9: PORTE FUNCTIONS
TABLE 5-10: SUMMARY OF REGISTERS ASSOCIATED WITH PORTE
Name Bit# Buffer Type Function
RE0/SEG05 bit0 ST Digital input or Segment Driver05
RE1/SEG06 bit1 ST Digital input or Segment Driver06
RE2/SEG07 bit2 ST Digital input or Segment Driver07
RE3/SEG08 bit3 ST Digital input or Segment Driver08
RE4/SEG09 bit4 ST Digital input or Segment Driver09
RE5/SEG10 bit5 ST Digital input or Segment Driver10
RE6/SEG11 bit6 ST Digital input or Segment Driver11
RE7/SEG27 bit7 ST Digital input or Segment Driver27 (not available on 64-pin devices)
Legend: ST = Schmitt Trigger input
Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Value on
Power-on
Reset
Value on all
other resets
09h PORTE RE7 RE6 RE5 RE4 RE3 RE2 RE1 RE0 0000 0000 0000 0000
89h TRISE PORTE Data Direction Control Register 1111 1111 1111 1111
10Dh LCDSE SE29 SE27 SE20 SE16 SE12 SE9 SE5 SE0 1111 1111 1111 1111
Legend: Shaded cells are not used by PORTE.