68HC705SP7 datasheet(87/230 Pages) FREESCALE

No. de pieza	68HC705SP7

Descripción Electrónicos	General Release Specification

PDF	230 Pages

Scroll/Zoom	100%

Fabricante Electrónico	FREESCALE [Freescale Semiconductor, Inc]

Página de inicio	http://www.freescale.com

Logo

87 / 230 page

Parallel Input/Output

Port B

MC68HC705JJ7/MC68HC705JP7 — Rev. 3.0

General Release Specification

Parallel Input/Output

7.4.5 PB0, PBI, PB2 and PB3 Logic

The typical I/O logic shown in Figure 7-8 is used for PB0, PB1, PB2, and

PB3 pins of port B. When these port B pins are programmed as an

output, reading the port bit actually reads the value of the data latch and

not the voltage on the pin itself. When these port B pins are programmed

as an input, reading the port bit reads the voltage level on the pin. The

data latch can always be written, regardless of the state of its DDRB bit.

The operations of the PB0:3 pins are summarized in Table 7-2.

Figure 7-8. PB0:3 Pin I/O Circuit

PORT BDATA

BIT PBx

DATA DIRECTION

BIT DDRBx

PULLDOWN

BIT PDIBx

PBx

ANALOG SUBSYSTEM,

AND PROGRAMMABLE

TIMER INPUT CAPTURE

READ $0005

WRITE $0001

READ $0001

WRITE $0011

PULLDOWN

DEVICE

RESET

(PINS PB0, PB1, PB2, PB3)

WRITE $0005

MASK OPTION REGISTER ($1FF1)

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

68HC705SP7 Datasheet(PDF) 87 Page - Freescale Semiconductor, Inc