C164CM_2 Datasheet, PDF (238/470 Pages) Infineon Technologies AG – 16-Bit Single-Chip Microcontroller

C164CM/C164SM
Derivatives
High-Speed Synchronous Serial Interface
12.1
Full-Duplex Operation
The various devices are connected through three lines. The definition of these lines is
always determined by the master: The line connected to the master’s data output pin
MTSR is the transmit line, the receive line is connected to its data input line MRST, and
the clock line is connected to pin SCLK. Only the device selected for master operation
generates and outputs the serial clock on pin SCLK. All slaves receive this clock, so their
pin SCLK must be switched to input mode (DP0H.7 = ‘0’). The output of the master’s shift
register is connected to the external transmit line, which in turn is connected to the
slaves’ shift register input. The output of the slaves’ shift register is connected to the
external receive line in order to enable the master to receive the data shifted out of the
slave. The external connections are hard-wired, the function and direction of these pins
are determined by the master or slave operation of the individual device.
Note: The shift direction shown in Figure 12-4 applies for MSB-first operation as well as
for LSB-first operation.
When initializing the devices in this configuration, select one device for master operation
(SSCMS = ‘1’); all others must be programmed for slave operation (SSCMS = ‘0’).
Initialization includes the operating mode of the device’s SSC and also the function of
the respective port lines (see Chapter 12.4).
Master
Shift Register
Clock
Device #1
MTSR
Transmit
MRST
SCLK
Receive
Clock
Device #2
MTSR
MRST
SCLK
Slave
Shift Register
Clock
Device #3
MTSR
MRST
SCLK
Slave
Shift Register
Clock
MCS01963
Figure 12-4 SSC Full-Duplex Configuration
User’s Manual
12-7
V1.0, 2002-02