C161RI_1 Datasheet, PDF (202/317 Pages) Siemens Semiconductor Group – 16-Bit CMOS Single-Chip Microcontroller

The High-Speed Synchronous Serial Interface
C161RI
12 The High-Speed Synchronous Serial Interface
The High-Speed Synchronous Serial Interface SSC provides flexible high-speed serial
communication between the C161RI and other microcontrollers, microprocessors or external
peripherals.
The SSC supports full-duplex and half-duplex synchronous communication up to 4 MBaud
(@ 16 MHz CPU clock). The serial clock signal can be generated by the SSC itself (master mode)
or be received from an external master (slave mode). Data width, shift direction, clock polarity and
phase are programmable. This allows communication with SPI-compatible devices. Transmission
and reception of data is double-buffered. A 16-bit baud rate generator provides the SSC with a
separate serial clock signal.
The high-speed synchronous serial interface can be configured in a very flexible way, so it can be
used with other synchronous serial interfaces (e.g. the ASC0 in synchronous mode), serve for
master/slave or multimaster interconnections or operate compatible with the popular SPI interface.
So it can be used to communicate with shift registers (IO expansion), peripherals (e.g. EEPROMs
etc.) or other controllers (networking). The SSC supports half-duplex and full-duplex
communication. Data is transmitted or received on pins MTSR/P3.9 (Master Transmit / Slave
Receive) and MRST/P3.8 (Master Receive / Slave Transmit). The clock signal is output or input on
pin SCLK/P3.13. These pins are alternate functions of Port 3 pins.
Ports & Direction Control
Alternate Functions
Data Registers
ODP3
E
DP3
P3
SCLK / P3.13
MTSR / P3.9
MRST / P3.8
SSCBR E
SSCTB E
SSCRB E
ODP3
DP3
SSCBR
SSCTB
SSCTIC
Port 3 Open Drain Control Register
Port 3 Direction Control Register
SSC Baud Rate Generator/Reload Register
SSC Transmit Buffer Register
SSC Transmit Interrupt Control Register
Control Registers
SSCCON
Interrupt Control
SSCTIC
SSCRIC
SSCEIC
P3
Port 3 Data Register
SSCCON SSC Control Register
SSCRB SSC Receive Buffer Register
SSCRIC SSC Receive Interrupt Control Register
SSCEIC SSC Error Interrupt Control Register
Figure 12-1
SFRs and Port Pins associated with the SSC
Semiconductor Group
12-1
1998-05-01