PIC17C7XX Datasheet, PDF (71/328 Pages) Microchip Technology – High-Performance 8-Bit CMOS EPROM Microcontrollers with 10-bit A/D

FIGURE 10-3: RA3 BLOCK DIAGRAM
Peripheral data in
D
Q
Data Bus
EN
PIC17C7XX
FIGURE 10-4: RA4 AND RA5 BLOCK
DIAGRAM
Serial port input signal
Data Bus
Q
D
RD_PORTA
(Q2)
RD_PORTA
(Q2)
Serial port output signals
Q CK
'1'
WR_PORTA
(Q4)
SDA out
SSP Mode
Note: I/O pin has protection diodes to VSS.
OE = SPEN,SYNC,TXEN, CREN, SREN for RA4
OE = SPEN (SYNC+SYNC,CSRC) for RA5
Note: I/O pins have protection diodes to VDD and VSS.
TABLE 10-1: PORTA FUNCTIONS
Name
Bit0 Buffer Type
Function
RA0/INT
bit0
ST
RA1/T0CKI
bit1
ST
RA2/SS/SCL bit2
ST
RA3/SDI/SDA bit3
ST
RA4/RX1/DT1 bit4
ST
RA5/TX1/CK1 bit5
ST
RBPU
bit7
—
Legend: ST = Schmitt Trigger input.
Input or external interrupt input.
Input or clock input to the TMR0 timer/counter, and/or an external interrupt
input.
Input/Output or slave select input for the SPI or clock input for the I²C bus.
Output is open drain type.
Input/Output or data input for the SPI or data for the I²C bus.
Output is open drain type.
Input or USART1 Asynchronous Receive or
USART1 Synchronous Data.
Input or USART1 Asynchronous Transmit or
USART1 Synchronous Clock.
Control bit for PORTB weak pull-ups.
TABLE 10-2: REGISTERS/BITS 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
MCLR,
WDT
10h, Bank 0
PORTA ⁽¹⁾ RBPU
—
RA5/
TX1/CK1
RA4/
RX1/DT1
RA3/
SDI/SDA
RA2/
SS/SCL
RA1/T0CKI
RA0/INT
05h, Unbanked T0STA
INTEDG T0SE T0CS T0PS3 T0PS2 T0PS1 T0PS0
—
13h, Bank 0 RCSTA1 SPEN RX9 SREN CREN
—
FERR
OERR
RX9D
15h, Bank 0 TXSTA1 CSRC TX9 TXEN SYNC
—
—
TRMT
TX9D
Legend: x = unknown, u = unchanged, - = unimplemented reads as '0'. Shaded cells are not used by PORTA.
Note 1: On any device reset, these pins are configured as inputs.
0-xx 11xx
0000 000-
0000 -00x
0000 --1x
0-uu 11uu
0000 000-
0000 -00u
0000 --1u
© 1998 Microchip Technology Inc.
DS30289A-page 71