PIC18F23K20-E/MLQTP MICROCHIP [Microchip Technology], PIC18F23K20-E/MLQTP Datasheet - Page 188

• Manufacturer Part Number: PIC18F23K20-E/MLQTP
• Description: 28/40/44-Pin Flash Microcontrollers with 10-Bit A/D and nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

PIC18F2XK20/4XK20
17.3.1
The MSSP module has four registers for SPI mode
operation. These are:
• SSPCON1 – Control Register
• SSPSTAT – STATUS register
• SSPBUF – Serial Receive/Transmit Buffer
• SSPSR – Shift Register (Not directly accessible)
SSPCON1 and SSPSTAT are the control and STATUS
registers in SPI mode operation. The SSPCON1 regis-
ter 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 17-1:
DS41303B-page 186
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:
R/W-0
SMP
Polarity of clock state is set by the CKP bit of the SSPCON1 register.
REGISTERS
SMP: Sample bit
SPI Master mode:
1 = Input data sampled at end of data output time
0 = Input data sampled at 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
R/W-0
CKE
SSPSTAT: MSSP STATUS REGISTER (SPI MODE)
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)
Advance Information
R-0
P
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
SSPSR is the shift register used for shifting data in
and out. SSPBUF provides indirect access to the
SSPSR register. SSPBUF is the buffer register to
which data bytes are written, and from which data
bytes are read.
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
© 2007 Microchip Technology Inc.
x = Bit is unknown
the
R-0
UA
SSPBUF
R-0
BF
is
bit 0
not