參數(shù)資料
型號: 16F872
廠商: Microchip Technology Inc.
英文描述: CAT 5E CROSSOVER PATCH CORD CABLE GREEN 10 FT
中文描述: 28引腳,8位閃存微控制器的CMOS
文件頁數(shù): 58/160頁
文件大?。?/td> 2600K
代理商: 16F872
PIC16F872
DS30221A-page 58
Preliminary
1999 Microchip Technology Inc.
9.1.1
MASTER MODE
The master can initiate the data transfer at any time
because it controls the SCK. The master determines
when the slave (Processor 2,
Figure 9-5
) is to broad-
cast data by the software protocol.
In Master mode, the data is transmitted/received as
soon as the SSPBUF register is written to. If the SPI
module is only going to receive, the SDO output could
be disabled (programmed as an input). The SSPSR
register will continue to shift in the signal present on the
SDI pin at the programmed clock rate. As each byte is
received, it will be loaded into the SSPBUF register as
if a normal received byte (interrupts and status bits
appropriately set). This could be useful in receiver
applications as a “l(fā)ine activity monitor”.
The clock polarity is selected by appropriately program-
ming bit CKP (SSPCON<4>). This then would give
waveforms for SPI communication as shown in
Figure 9-6
,
Figure 9-8
and
Figure 9-9
where the MSb is
transmitted first. In Master mode, the SPI clock rate (bit
rate) is user programmable to be one of the following:
F
OSC
/4 (or T
CY
)
F
OSC
/16 (or 4 T
CY
)
F
OSC
/64 (or 16 T
CY
)
Timer2 output/2
This allows a maximum bit clock frequency (at 20 MHz)
of 5.0 MHz.
Figure 9-6
shows the waveforms for Master mode.
When CKE = 1, the SDO data is valid before there is a
clock edge on SCK. The change of the input sample is
shown based on the state of the SMP bit. The time
when the SSPBUF is loaded with the received data is
shown.
FIGURE 9-2:
SPI MODE TIMING, MASTER MODE
SCK (CKP = 0,
CKE = 0)
SDI (SMP = 0)
SSPIF
bit7
bit6
bit5
bit4
bit3
bit2
bit1
bit0
SDI (SMP = 1)
SCK (CKP = 0,
CKE = 1)
SCK (CKP = 1,
CKE = 0)
SCK (CKP = 1,
CKE = 1)
SDO
bit7
bit7
bit0
bit0
相關(guān)PDF資料
PDF描述
16F876A 28/40-pin Enhanced FLASH Microcontrollers
16F876 CAT 5E CROSSOVER, GREEN 15 FT PATCH CABLE
16F877 CAT 5E CROSSOVER PATCH CORD CABLE GREEN 20 FT
16FL100S02 6A, 12A AND 16A FAST RECOVERY RECTIFIERS
16FL100S05 6A, 12A AND 16A FAST RECOVERY RECTIFIERS
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
16F876 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:28/40-pin 8-Bit CMOS FLASH Microcontrollers
16F876A 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:28/40-pin Enhanced FLASH Microcontrollers
16F877 制造商:MICROCHIP 制造商全稱:Microchip Technology 功能描述:28/40-pin 8-Bit CMOS FLASH Microcontrollers
16F9040 制造商:未知廠家 制造商全稱:未知廠家 功能描述:COMPACT DIGITALMULTIMETER TRUE RMS
16F9041 制造商:未知廠家 制造商全稱:未知廠家 功能描述:COMPACT DMM MIT RS232