參數(shù)資料
型號: 68HC05M68HC
廠商: Motorola, Inc.
英文描述: HCMOS Microcontroller Unit
中文描述: HCMOS微控制器
文件頁數(shù): 53/130頁
文件大?。?/td> 1541K
代理商: 68HC05M68HC
Input/Output Ports
Port B
MC68HC705P6A
Rev. 2.0
Advance Information
MOTOROLA
Input/Output Ports
53
6.4 Port B
Port B is a 3-bit bidirectional port which can share pins PB5
PB7 with
the SIOP communications subsystem. The port B data register is located
at address $0001 and its data direction register (DDR) is located at
address $0005. The contents of the port B data register are
indeterminate at initial powerup and must be initialized by user software.
Reset does not affect the data registers, but clears the DDRs, thereby
setting all of the port pins to input mode. Writing a 1 to a DDR bit sets the
corresponding port pin to output mode (see
Figure 6-2
).
Port B may be used for general I/O applications when the SIOP
subsystem is disabled. The SPE bit in register SPCR is used to
enable/disable the SIOP subsystem. When the SIOP subsystem is
enabled, port B registers are still accessible to software. Writing to either
of the port B registers while a data transfer is under way could corrupt
the data. See
Section 7. Serial Input/Output Port (SIOP)
for a
discussion of the SIOP subsystem.
Figure 6-2. Port B I/O Circuitry
READ $0001
WRITE $0001
READ $0005
DATA
REGISTER BIT
I/O
PIN
OUTPUT
INTERNAL HC05
DATA BUS
RESET
(RST)
WRITE $0005
DATA DIRECTION
REGISTER BIT
相關(guān)PDF資料
PDF描述
68HC070KH12 8 BIT MICROCONTROLLER UNITS
68HC08KH12 8 BIT MICROCONTROLLER UNITS
68HC08M68HC HCMOS Microcontroller Unit
68HC11 Technical Data
68HC12 Advance Information
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
68HC05P4A 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:SPECIFICATION (General Release)
68HC05P4A_1 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:SPECIFICATION (General Release)
68HC05P5 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:SPECIFICATION(General Release)
68HC05P9A 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:SPECIFICATION(General Release)
68HC05P9A_1 制造商:FREESCALE 制造商全稱:Freescale Semiconductor, Inc 功能描述:SPECIFICATION(General Release)