XC164-16 Datasheet, PDF (297/417 Pages) Infineon Technologies AG – 16-Bit Single-Chip Microcontroller with C166SV2 Core Volume 2 (of 2): Peripheral Units

XC164-16 Derivatives
Peripheral Units (Vol. 2 of 2)
High-Speed Synchronous Serial Interface (SSC)
clock, changes between one cycle before and two cycles after the latching edge of the
shift clock signal SCLK. This condition sets the error flag PE and, when enabled via bit
PEN, the error interrupt request line EIRQ.
A Baudrate Error (Slave Mode) is detected when the incoming clock signal deviates
from the programmed baudrate by more than 100%, i.e. it either is more than double or
less than half the expected baudrate. This condition sets the error flag BE and, when
enabled via bit BEN, the error interrupt request line EIRQ. Using this error detection
capability requires that the slave’s baudrate generator is programmed to the same
baudrate as the master device. This feature detects false, additional or missing, pulses
on the clock line (within a certain frame).
Note: If this error condition occurs and bit AREN = 1, an automatic reset of the SSC will
be performed in case of this error. This is done to re-initialize the SSC if too few or
too many clock pulses have been detected.
A Transmit Error (Slave Mode) is detected when a transfer was initiated by the master
(SCLK gets active), but the transmit buffer SSCx_TB of the slave was not updated since
the last transfer. This condition sets the error flag TE and, when enabled via bit TEN, the
error interrupt request line EIRQ. If a transfer starts while the transmit buffer is not
updated, the slave will shift out the ‘old’ contents of the shift register, which usually is the
data received during the last transfer. This may lead to corruption of the data on the
transmit/receive line in half-duplex mode (open-drain configuration) if this slave is not
selected for transmission. This mode requires that slaves not selected for transmission
only shift out ones; that is, their transmit buffers must be loaded with FFFF_H prior to any
transfer.
Note: A slave with push/pull output drivers not selected for transmission will usually have
its output drivers switched off. However, in order to avoid possible conflicts or
misinterpretations, it is recommended to always load the slave's transmit buffer
prior to any transfer.
The cause of an error interrupt request (receive, phase, baudrate, transmit error) can be
identified by the error status flags in control register SSCx_CON.
Note: The error status flags TE, RE, PE, and BE, are not reset automatically upon entry
into the error interrupt service routine, but must be cleared by software.
User’s Manual
SSC_X, V2.0
20-15
V2.1, 2004-03