PIC16F1847_13 Datasheet, PDF (235/440 Pages) Microchip Technology – 18/20/28-Pin Flash Microcontrollers with XLP Technology

PIC16(L)F1847
FIGURE 25-4:
SPI MASTER AND MULTIPLE SLAVE CONNECTION
SPI Master
SCKx
SDOx
SDIx
General I/O
General I/O
General I/O
SCKx
SDIx
SDOx
SSx
SPI Slave
#1
SCKx
SDIx
SDOx
SSx
SPI Slave
#2
SCKx
SDIx
SDOx
SSx
SPI Slave
#3
25.2.1 SPI MODE REGISTERS
The MSSPx module has five registers for SPI mode
operation. These are:
• MSSPx STATUS register (SSPxSTAT)
• MSSPx Control Register 1 (SSPxCON1)
• MSSPx Control Register 3 (SSPxCON3)
• MSSPx Data Buffer register (SSPxBUF)
• MSSPx Address register (SSPxADD)
• MSSPx Shift register (SSPxSR)
(Not directly accessible)
SSPxCON1 and SSPxSTAT are the control and
STATUS registers in SPI mode operation. The
SSPxCON1 register is readable and writable. The
lower six bits of the SSPxSTAT are read-only. The
upper two bits of the SSPxSTAT are read/write.
In SPI master mode, SSPxADD can be loaded with a
value used in the Baud Rate Generator. More informa-
tion on the Baud Rate Generator is available in
Section 25.7 “Baud Rate Generator”.
SSPxSR is the shift register used for shifting data in
and out. SSPxBUF provides indirect access to the
SSPxSR register. SSPxBUF is the buffer register to
which data bytes are written, and from which data
bytes are read.
In receive operations, SSPxSR and SSPxBUF
together create a buffered receiver. When SSPxSR
receives a complete byte, it is transferred to SSPxBUF
and the SSPxIF interrupt is set.
During transmission, the SSPxBUF is not buffered. A
write to SSPxBUF will write to both SSPxBUF and
SSPxSR.
 2011-2013 Microchip Technology Inc.
Preliminary
DS40001453D-page 235