C511_1 Datasheet, PDF (76/128 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

On-Chip Peripheral Units
6.4 Synchronous Serial Channel (SSC)
The SAB-C511/513 microcontrollers provide 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.
6.4.1 SSC Block Diagram
Figure 6-6-30 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 P1.3/SRI (SSC Receiver In) and P1.4/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 2
Clock Divider
...
Clock Selection
Interrupt
STB
Shift Register
SRB
Receive Buffer Register
Pin
Control
Logic
Pin P1.2 / SCLK
Pin P1.3 / SRI
Pin P1.4 / STO
Pin P1.5 / SLS
SCIEN
Int. Enable Reg.
SSCCON
Control Register
Control Logic
SCF
Status Register
Figure 6-30
SSC Blockdiagram
Semiconductor Group
Internal Bus
6-43
MCB02438