PIC17C75X Datasheet, PDF (123/320 Pages) Microchip Technology – High-Performance 8-Bit CMOS EPROM Microcontrollers

15.0 SYNCHRONOUS SERIAL
PORT (SSP) MODULE
The Synchronous Serial Port (SSP) module is a serial
interface useful for communicating with other periph-
eral or microcontroller devices. These peripheral
devices may be serial EEPROMs, shift registers, dis-
play drivers, A/D converters, etc. The SSP module can
operate in one of two modes:
• Serial Peripheral Interface (SPI)
• Inter-Integrated Circuit (I²C)
Refer to Application Note AN578, "Use of the SSP
Module in the I ²C Multi-Master Environment."
Figure 15-1, Figure 15-2, and Figure 15-3 show the
block diagrams for the three different modes of opera-
tion.
FIGURE 15-1: SPI MODE BLOCK
DIAGRAM
Internal
data bus
Read
Write
SSPBUF reg
SDI
SDO
SS
SCK
SSPSR reg
bit0
shift
clock
SS Control
Enable
Edge
Select
2
Clock Select
SSPM3:SSPM0
SMP:CKE ₄
2
TMR2 output
2
Edge
Select
Prescaler TOSC
4, 16, 64
Data to TX/RX in SSPSR
Data direction bit
PIC17C75X
FIGURE 15-2: I²C SLAVE MODE BLOCK
DIAGRAM
Read
Internal
data bus
Write
SCL
SDA
SSPBUF reg
shift
clock
SSPSR reg
MSb
LSb
Match detect
Addr Match
SSPADD reg
Start and
Stop bit detect
Set, Reset
S, P bits
(SSPSTAT reg)
FIGURE 15-3: I²C MASTER MODE BLOCK
DIAGRAM
Read
SSPADD<6:0>
7
Baud Rate Generator
Internal
data bus
Write
SCL
SDA
SSPBUF reg
shift
clock
SSPSR reg
MSb
LSb
Match detect
Addr Match
SSPADD reg
Start and Stop bit
detect / generate
Set/Clear S bit
and
Clear/Set P, bits
(SSPSTAT reg)
and Set SSPIF
© 1997 Microchip Technology Inc.
Preliminary
DS30264A-page 123