XC161 Datasheet, PDF (343/419 Pages) Infineon Technologies AG – 16-Bit Single-Chip Microcontroller with C166SV2 Core Volume 2 (of 2): Peripheral Units

XC161 Derivatives
Peripheral Units (Vol. 2 of 2)
Serial Data Link Module SDLM
22.2.4 In-Frame Response (IFR) Operation
The module supports automatic IFR transmission for type 1, 2 IFR for three-byte
consolidated headers (no CPU load required). If the IFRs are handled via the transmit
buffer, TxCPU indicates the number of bytes to be transmitted.
• If automatic IFR transmission function is not possible (single byte or one byte
consolidated headers): If bit IFREN is not set, type 1 and 2 are handled via the
transmit buffer, too. If IFREN is set, the value stored in IFRVAL will be transmitted if
bit TxIRF is set.
• In case of automatic IFR transmission, register IFRVAL delivers the source ID. The
value has to be written by the CPU first.
• IFR type 3 transmission can only be handled by the transmit buffer.
• Setting bit TxIFR initiates an IFR transmission (if automatic IFR not possible).
• Normalization symbol can be configured by the NB configuration bit.
• If IFR with CRC (Type 3, CRCEN = 1) is used, bit CRCERR indicates CRC error
conditions.
• If register IFRVAL is used for transmission, no CRC will be sent out (not depending
on CRCEN). If the transmit buffer is used, CRC will be sent out if bit CRCEN is set.
• Bit HEADER indicates complete reception of header byte(s) in the receive buffer on
bus side.
Transmission of type 1 and type 2 IFRs for single byte headers and one byte
consolidated headers is also accomplished by bit TxIFR, which has to be set by
software. In case of automatic IFR (for type 1, 2 for three byte consolidated headers and
IRFEN = 1), bit TxIFR is not needed.
3-byte consolidated headers: If IFREN is set, automatic response to type 1 and type 2
IFRs via the IFRVAL register is enabled. Type 3 IFR is sent by writing the IFR to the
transmit buffer and then setting bit TxIFR. If IFREN is not set, all IFRs are transmitted via
the transmit buffer if TxIFR is set.
Single byte headers and one byte consolidated headers: As there is no information in the
header to indicate if an IFR is required, automatic transmission of Type 1 and 2 IFRs is
not possible. If IFRs are used in the system, the header interrupt should be enabled in
order to give time to decode the header through software to determine if an IFR is
required. IFR transmission is always initiated by setting bit TxIFR. Type 3 IFR is always
done via the transmit buffer, whereas types 1, 2 are handled either via the transmit buffer
(IFREN = 0) or register IFRVAL (IFREN = 1).
User’s Manual
SDLM_X, V2.0
22-12
V2.2, 2004-01