C161U
The High-Speed Synchronous Serial Interface
Preliminary Data Sheet
310
02.2000
PRELIMINARY
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The High-Speed Synchronous Serial Interface
The High-Speed Synchronous Serial Interface SSC provides flexible high-speed serial
communication between the C161U and other microcontrollers, microprocessors or
external peripherals.
The SSC supports full-duplex and half-duplex synchronous communication up to 18
MBaud in SSC Master Mode and 9 MBaud in SSC Slave Mode (@ 36 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 (eg. the ASC 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 (eg. 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.
Figure 98
SFRs and Port Pins associated with the SSC
SCLK / P3.13
MTSR / P3.9
MRST / P3.8
ODP3
Port 3 Open Drain Control Register
DP3
Port 3 Direction Control Register
SSCBR
SSC Baud Rate Generator/Reload Register
SSCTB
SSC Transmit Buffer Register
SSCTIC
SSC Transmit Interrupt Control Register
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
ODP3
Ports & Direction Control
Alternate Functions
Data Registers
Control Registers
Interrupt Control
SSCBR
SSCCON
SSCTIC
DP3
P3
SSCTB
SSCRB
SSCRIC
SSCEIC