C515C_9711 Datasheet, PDF (128/268 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

On-Chip Peripheral Components
C515C
6.4 SSC Interface
The C515C microcontroller provides a Synchronous Serial Channel unit, the SSC. This interface is
compatible to the popular SPI serial bus interface. It can be used for simple I/O expansion via shift
registers, for connection of a variety of peripheral components, such as A/D converters, EEPROMs
etc., or for allowing several microcontrollers to be interconnected in a master/slave structure. It
supports full-duplex or half-duplex operation and can run in a master or a slave mode.
Figure 6-37 shows the block diagram of the SSC. The central element of the SSC is an 8-bit shift
register. The input and the output of this shift register are each connected via a control logic to the
pin P4.2 / SRI (SSC Receiver In) and P4.3 / STO (SSC Transmitter Out). This shift register can be
written to (SFR STB) and can be read through the Receive Buffer Register SRB.
f _OSC
Clock Divider
Clock Selection
Interrupt
STB
Shift Register
SRB
Receive Buffer Register
SCIEN
Int. Enable Reg.
SSCCON
Control Register
Control Logic
SCF
Status Register
Pin
Control
Logic
Internal Bus
P4.1/SCLK
P4.2/SRI
P4.3/STO
P4.4/SLS
MCB02735
Figure 6-37
SSC Block Diagram
Semiconductor Group
6-65
1997-11-01