PIC16C76-10/JW Microchip Technology, PIC16C76-10/JW Datasheet - Page 87

• Manufacturer Part Number: PIC16C76-10/JW
• Description: 8-Bit CMOS Microcontrollers with A/D Converter
• Manufacturer: Microchip Technology

The SS pin allows a synchronous slave mode. The
SPI must be in slave mode (SSPCON<3:0> = 04h)
and the TRISA<5> bit must be set for the synchro-
nous slave mode to be enabled. When the SS pin is
low, transmission and reception are enabled and
the SDO pin is driven. When the SS pin goes high,
the SDO pin is no longer driven, even if in the mid-
dle of a transmitted byte, and becomes a floating
output. If the SS pin is taken low without resetting
SPI mode, the transmission will continue from the
point at which it was taken high. External pull-up/
pull-down resistors may be desirable, depending on the
application.
FIGURE 11-11: SPI MODE TIMING, MASTER MODE (PIC16C76/77)
FIGURE 11-12: SPI MODE TIMING (SLAVE MODE WITH CKE = 0) (PIC16C76/77)
SCK (CKP = 0,
SCK (CKP = 0,
SCK (CKP = 1,
SCK (CKP = 1,
SDO
SDI (SMP = 0)
SCK (CKP = 0)
SCK (CKP = 1)
1997 Microchip Technology Inc.
SDI (SMP = 1)
SDO
SDI (SMP = 0)
SSPIF
SS (optional)
SSPIF
CKE = 0)
CKE = 1)
CKE = 0)
CKE = 1)
bit7
bit7
bit7
bit7
bit7
bit6
bit6
72 73 73A 74 74A 76 77
Applicable Devices
bit5
bit5
bit4
bit4
.
To emulate two-wire communication, the SDO pin can
be connected to the SDI pin. When the SPI needs to
operate as a receiver the SDO pin can be configured as
an input. This disables transmissions from the SDO.
The SDI can always be left as an input (SDI function)
since it cannot create a bus conflict.
Note:
Note:
bit3
bit3
When the SPI is in Slave Mode with SS pin
control enabled, (SSPCON<3:0> = 0100)
the SPI module will reset if the SS pin is set
to V
If the SPI is used in Slave Mode with
CKE = '1', then the SS pin control must be
enabled.
DD
.
bit2
bit2
PIC16C7X
bit1
bit1
DS30390E-page 87
bit0
bit0
bit0
bit0
bit0