参数资料
型号: MC68HC05C8ACB
厂商: MOTOROLA INC
元件分类: 微控制器/微处理器
英文描述: 8-BIT, MROM, 2.1 MHz, MICROCONTROLLER, PDIP42
封装: SHRINK, PLASTIC, DIP-42
文件页数: 140/156页
文件大小: 755K
代理商: MC68HC05C8ACB
NON-DISCLOSURE
AGREEMENT
REQUIRED
Serial Peripiheral Interface (SPI)
General Release Specification
MC68HC05C8A Rev. 3.0
84
Serial Peripiheral Interface (SPI)
MOTOROLA
10.4.4 Slave Select (SS)
The slave select (SS) input line is used to select a slave device. It has to
be low prior to data transactions and must stay low for the duration of the
transaction.
The SS line on the master must be tied high. If it goes low, a mode fault
error flag (MODF) is set in the SPSR.
When CPHA = 0, the shift clock is the OR of SS with SCK. In this clock
phase mode, SS must go high between successive characters in an SPI
message. When CPHA = 1, SS may be left low for several SPI
characters. In cases where there is only one SPI slave MCU, its SS line
could be tied to VSS as long as CPHA = 1 clock modes are used.
10.5 Functional Description
Figure 10-2 shows a block diagram of the serial peripheral interface
circuitry. When a master device transmits data to a slave via the MOSI
line, the slave device responds by sending data to the master device via
the master’s MISO line. This implies full duplex transmission with both
data out and data in synchronized with the same clock signal. Thus, the
byte transmitted is replaced by the byte received and eliminates the
need for separate transmit-empty and receive-full status bits. A single
status bit (SPIF) is used to signify that the I/O operation has been
completed.
The SPI data register (SPDR) is double buffered on read, but not on
write. If a write is performed during data transfer, the transfer occurs
uninterrupted, and the write will be unsuccessful. This condition will
cause the write collision (WCOL) status bit in the SPSR to be set. After
a data byte is shifted, the SPIF flag of the SPSR is set.
In the master mode, the SCK pin is an output. It idles high or low,
depending on the CPOL bit in the SPCR, until data is written to the shift
register, at which point eight clocks are generated to shift the eight bits
of data and then SCK goes idle again.
相关PDF资料
PDF描述
MC68HC16Z3MFC20 16-BIT, MROM, MICROCONTROLLER, PQFP132
MC68HC705C4FN 8-BIT, OTPROM, 2.1 MHz, MICROCONTROLLER, PQCC44
MC68HC05D9FN 8-BIT, MROM, 2 MHz, MICROCONTROLLER, PQCC44
M37705M2A001SP 16-BIT, MROM, 16 MHz, MICROCONTROLLER, PDIP64
M37700SFP 16-BIT, 8 MHz, MICROCONTROLLER, PQFP80
相关代理商/技术参数
参数描述
MC68HC05C8ACFN 制造商:Motorola Inc 功能描述:MicroController, 8-Bit, 44 Pin, Plastic, PLCC
MC68HC05C9 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:TECHNICAL DATA
MC68HC05C9A 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:Microcontrollers
MC68HC05C9AB 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:Microcontrollers
MC68HC05C9AFB 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:Microcontrollers