PIC16F526-ISLASHP datasheet(27/122 Pages) MICROCHIP

27 / 122 page

 2010 Microchip Technology Inc.

DS41326D-page 27

PIC16F526

6.0

I/O PORT

As with any other register, the I/O register(s) can be

written and read under program control. However, read

instructions (e.g., MOVF PORTB,W) always read the I/O

pins independent of the pin’s Input/Output modes. On

Reset, all I/O ports are defined as input (inputs are at high-

impedance) since the I/O control registers are all set.

6.1

PORTB

PORTB is a 6-bit I/O register. Only the low-order 6 bits

are used (RB<5:0>). Bits 7 and 6 are unimplemented

and read as ‘0’s. Please note that RB3 is an input-only

pin. The Configuration Word can set several I/O’s to

alternate functions. When acting as alternate functions,

the pins will read as ‘0’ during a port read. Pins RB0,

RB1, RB3 and RB4 can be configured with weak pull-

ups and also for wake-up on change. The wake-up on

change and weak pull-up functions are not pin

selectable. If RB3/MCLR is configured as MCLR, weak

pull-up is always on and wake-up on change for this pin

is not enabled.

6.2

PORTC

PORTC is a 6-bit I/O register. Only the low-order 6 bits

are used (RC<5:0>). Bits 7 and 6 are unimplemented

and read as ‘0’s.

6.3

TRIS Register

The Output Driver Control register is loaded with the

contents of the W register by executing the TRIS f

instruction. A ‘1’ from a TRIS register bit puts the

corresponding output driver in a High-Impedance

mode. A ‘0’ puts the contents of the output data latch

on the selected pins, enabling the output buffer. The

exceptions are RB3, which is input-only and the T0CKI

pin, which may be controlled by the OPTION register.

See Register 4-2.

TRIS registers are “write-only”. Active bits in these

registers are set (output drivers disabled) upon Reset.

TABLE 6-1:

WEAK PULL-UP ENABLED PINS

Device

RB0 Weak Pull-up RB1 Weak Pull-up RB3 Weak Pull-up(1)

RB4 Weak Pull-up

PIC16F526

Yes

Note 1: When MCLREN = 1, the weak pull-up on RB3/MCLR is always enabled.

PORTB: PORTB REGISTER

U-0

R/W-x

—

RB5

RB4

RB3

RB2

RB1

RB0

bit 7

bit 0

Legend:

R = Readable bit

W = Writable bit

U = Unimplemented bit, read as ‘0’

-n = Value at POR

‘1’ = Bit is set

‘0’ = Bit is cleared

x = Bit is unknown

bit 7-6

Unimplemented: Read as ‘0’

bit 5-0

RB<5:0>: PORTB I/O Pin bits

1 = Port pin is >VIH min.

0 = Port pin is <VIL max.

PIC16F526-I/P 数据表(PDF) 27 Page - Microchip Technology

PIC16F526-I/P 数据表(HTML) 27 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

数据表下载