PIC16F87XA
9.3.8
SLEEP OPERATION
9.3.10
BUS MODE COMPATIBILITY
In Master mode, all module clocks are halted, and the
transmission/reception will remain in that state until the
device wakes from SLEEP. After the device returns to
normal mode, the module will continue to transmit/
receive data.
Table 9-1 shows the compatibility between the stan-
dard SPI modes and the states the CKP and CKE con-
trol bits.
TABLE 9-1:
SPI BUS MODES
In Slave mode, the SPI transmit/receive shift register
operates asynchronously to the device. This allows the
device to be placed in SLEEP mode, and data to be
shifted into the SPI transmit/receive shift register.
When all 8-bits have been received, the MSSP inter-
rupt flag bit will be set and if enabled, will wake the
device from SLEEP.
Control Bits State
Standard SPI Mode
Terminology
CKP
CKE
0, 0
0, 1
1, 0
1, 1
0
0
1
1
1
0
1
0
9.3.9
EFFECTS OF A RESET
There is also a SMP bit which controls when the data is
sampled.
A reset disables the MSSP module and terminates the
current transfer.
TABLE 9-2:
REGISTERS ASSOCIATED WITH SPI OPERATION
Value on
POR,
BOR
Value on
all other
RESETS
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
INTCON
GIE/GIEH
PEIE/
GIEL
TMR0IE INT0IE
RBIE
TMR0IF
CCP1IF
INT0IF
RBIF
0000 000x 0000 000u
(1)
PIR1
PIE1
PSPIF
ADIF
ADIE
ADIP
RCIF
RCIE
RCIP
TXIF
TXIE
TXIP
SSPIF
SSPIE
SSPIP
TMR2IF TMR1IF 0000 0000 0000 0000
(1)
PSPIE
CCP1IE TMR2IE TMR1IE 0000 0000 0000 0000
CCP1IP TMR2IP TMR1IP 0000 0000 0000 0000
1111 1111 1111 1111
(1)
IPR1
PSPIP
TRISC
PORTC Data Direction Register
SSPBUF Synchronous Serial Port Receive Buffer/Transmit Register
xxxx xxxx uuuu uuuu
SSPCON
TRISA
WCOL
—
SSPOV SSPEN
PORTA Data Direction Register
CKE D/A
CKP
SSPM3
SSPM2
R/W
SSPM1
UA
SSPM0 0000 0000 0000 0000
--11 1111 --11 1111
SSPSTAT
SMP
P
S
BF
0000 0000 0000 0000
Legend: x = unknown, u = unchanged, - = unimplemented read as '0'.
Shaded cells are not used by the MSSP in SPI mode.
Note 1: The PSPIF, PSPIE and PSPIP bits are reserved on 28-pin devices. Always maintain these bits clear.
2001 Microchip Technology Inc.
Advance Information
DS39582A-page 77
MICROCHIP [ MICROCHIP ]
