PIC18F25K80 MICROCHIP [Microchip Technology], PIC18F25K80 Datasheet - Page 294

• Manufacturer Part Number: PIC18F25K80
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F66K80 FAMILY
21.3.1
The MSSP module has four registers for SPI mode
operation. These are:
• MSSP Control Register 1 (SSPCON1)
• MSSP Status Register (SSPSTAT)
• Serial Receive/Transmit Buffer Register
• MSSP Shift Register (SSPSR) – Not directly
SSPCON1 and SSPSTAT are the control and status
registers in SPI mode operation. The SSPCON1
register is readable and writable. The lower 6 bits of
the SSPSTAT are read-only. The upper two bits of the
SSPSTAT are read/write.
REGISTER 21-1:
DS39977C-page 294
bit 7
Legend:
R = Readable bit
-n = Value at POR
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
Note 1:
(SSPBUF)
accessible
R/W-0
SMP
Polarity of clock state is set by the CKP bit (SSPCON1<4>).
REGISTERS
SMP: Sample bit
SPI Master mode:
1 = Input data sampled at the end of data output time
0 = Input data sampled at the middle of data output time
SPI Slave mode:
SMP must be cleared when SPI is used in Slave mode.
CKE: SPI Clock Select bit
1 = Transmit occurs on transition from active to Idle clock state
0 = Transmit occurs on transition from Idle to active clock state
D/A: Data/Address bit
Used in I
P: Stop bit
Used in I
S: Start bit
Used in I
R/W: Read/Write Information bit
Used in I
UA: Update Address bit
Used in I
BF: Buffer Full Status bit (Receive mode only)
1 = Receive complete, SSPBUF is full
0 = Receive not complete, SSPBUF is empty
CKE
R/W-0
SSPSTAT: MSSP STATUS REGISTER (SPI MODE)
(1)
2
2
2
2
2
C™ mode only.
C mode only. This bit is cleared when the MSSP module is disabled; SSPEN is cleared.
C mode only.
C mode only.
C mode only.
W = Writable bit
‘1’ = Bit is set
R-0
D/A
(1)
R-0
Preliminary
P
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
SSPSR is the shift register used for shifting data in or
out. SSPBUF is the buffer register to which data bytes
are written to or read from.
In receive operations, SSPSR and SSPBUF together,
create a double-buffered receiver. When SSPSR
receives a complete byte, it is transferred to SSPBUF
and the SSPIF interrupt is set.
During
double-buffered. A write to SSPBUF will write to both
SSPBUF and SSPSR.
R-0
S
transmission,
R/W
R-0
 2011 Microchip Technology Inc.
x = Bit is unknown
the
R-0
UA
SSPBUF
R-0
BF
is
bit 0
not