參數(shù)資料
型號(hào): PIC18F458TEPSQTP
廠商: Microchip Technology Inc.
英文描述: High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN
中文描述: 高性能,28/40-Pin增強(qiáng)型閃存微控制器和CAN
文件頁(yè)數(shù): 146/384頁(yè)
文件大?。?/td> 3119K
代理商: PIC18F458TEPSQTP
PIC18FXX8
DS41159B-page 144
Preliminary
2002 Microchip Technology Inc.
17.3.2
OPERATION
When initializing the SPI, several options need to be
specified. This is done by programming the appropriate
control bits (SSPCON1<5:0>) and SSPSTAT<7:6>.
These control bits allow the following to be specified:
Master mode (SCK is the clock output)
Slave mode (SCK is the clock input)
Clock Polarity (IDLE state of SCK)
Data input sample phase (middle or end of data
output time)
Clock edge (output data on rising/falling edge of
SCK)
Clock Rate (Master mode only)
Slave Select mode (Slave mode only)
The MSSP consists of a transmit/receive Shift Register
(SSPSR) and a buffer register (SSPBUF). The SSPSR
shifts the data in and out of the device, MSb first. The
SSPBUF holds the data that was written to the SSPSR,
until the received data is ready. Once the 8 bits of data
have been received, that byte is moved to the SSPBUF
register. Then the buffer full detect bit, BF
(SSPSTAT<0>), and the interrupt flag bit, SSPIF, are
set. This double buffering of the received data
(SSPBUF) allows the next byte to start reception before
reading the data that was just received. Any write to the
SSPBUF register during transmission/reception of data
will be ignored, and the write collision detect bit, WCOL
(SSPCON1<7>), will be set. User software must clear
the WCOL bit so that it can be determined if the follow-
ing write(s) to the SSPBUF register completed
successfully.
When the application software is expecting to receive
valid data, the SSPBUF should be read before the next
byte of data to transfer is written to the SSPBUF. Buffer
full bit, BF (SSPSTAT<0>), indicates when SSPBUF
has been loaded with the received data (transmission
is complete). When the SSPBUF is read, the BF bit is
cleared. This data may be irrelevant if the SPI is only a
transmitter. Generally, the MSSP Interrupt is used to
determine when the transmission/reception has com-
pleted. The SSPBUF must be read and/or written. If the
interrupt method is not going to be used, then software
polling can be done to ensure that a write collision does
not occur. Example 17-1 shows the loading of the
SSPBUF (SSPSR) for data transmission.
The SSPSR is not directly readable or writable, and
can only be accessed by addressing the SSPBUF reg-
ister. Additionally, the MSSP status register (SSPSTAT)
indicates the various status conditions.
EXAMPLE 17-1:
LOADING THE SSPBUF (SSPSR) REGISTER
LOOP BTFSS SSPSTAT, BF ;Has data been received(transmit complete)
BRA LOOP ;No
MOVF SSPBUF, W ;WREG reg = contents of SSPBUF
MOVWF RXDATA ;Save in user RAM, if data is meaningful
MOVF TXDATA, W ;W reg = contents of TXDATA
MOVWF SSPBUF ;New data to xmit
相關(guān)PDF資料
PDF描述
PIC18F458TEPTQTP High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN
PIC18F458TEPTSQTP High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN
PIC18F458TESOQTP High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN
PIC18F458TESOSQTP High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN
PIC18F458TESPQTP High Performance, 28/40-Pin Enhanced FLASH Microcontrollers with CAN
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
PIC18F458T-I/L 功能描述:8位微控制器 -MCU 32KB 1536 RAM 34 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線(xiàn)寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
PIC18F458T-I/PT 功能描述:8位微控制器 -MCU 32KB 1536 RAM 34 I/O RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線(xiàn)寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
PIC18F458T-I/PTG 功能描述:8位微控制器 -MCU 32KB 1536 RAM 34 I/O Lead Free Package RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線(xiàn)寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
PIC18F45J10-E/ML 功能描述:8位微控制器 -MCU 32 KB Flash 1 KB RAM RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線(xiàn)寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
PIC18F45J10-E/P 功能描述:8位微控制器 -MCU 32 KB Flash 1 KB RAM RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線(xiàn)寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT