PIC16F87-E Datasheet, PDF (54/228 Pages) Microchip Technology – 18/20/28-Pin Enhan lashMicrocontrollers with nanoWatt Technology

PIC16F87/88
TABLE 5-2: SUMMARY OF REGISTERS ASSOCIATED WITH PORTA
Address Name Bit 7 Bit 6
Bit 5
Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Value on
POR, BOR
Value on
all other
Resets
05h
PORTA
RA7 RA6
RA5
RA4 RA3 RA2 RA1 RA0 xxxx 0000⁽¹⁾ uuuu 0000⁽¹⁾
xxx0 0000⁽²⁾ uuu0 0000⁽²⁾
85h
TRISA TRISA7 TRISA6 TRISA5⁽³⁾ PORTA Data Direction Register
1111 1111 1111 1111
9Fh
ADCON1 ADFM ADCS2 VCFG1 VCFG0 —
—
—
— 0000 ---- 0000 ----
9Bh
ANSEL⁽⁴⁾
—
ANS6 ANS5 ANS4 ANS3 ANS2 ANS1 ANS0 -111 1111 -111 1111
Legend:
Note 1:
2:
3:
4:
x = unknown, u = unchanged, - = unimplemented locations read as ‘0’. Shaded cells are not used by PORTA.
This value applies only to the PIC16F87.
This value applies only to the PIC16F88.
Pin 5 is an input only; the state of the TRISA5 bit has no effect and will always read ‘1’.
PIC16F88 device only.
FIGURE 5-1:
BLOCK DIAGRAM OF RA0/AN0:RA1/AN1 PINS
Data
Bus
WR
PORTA
WR
TRISA
D
Q
CK Q
Data Latch
D
Q
CK Q
TRIS Latch
RD TRISA
VDD
VDD
P
N
I/O pin
VSS
Analog
Input Mode
TTL
Input Buffer
Q
D
EN
RD PORTA
To Comparator
To A/D Module Channel Input (PIC16F88 only)
DS30487C-page 52
 2005 Microchip Technology Inc.