5. Write to set MODEM[RXRTSE] = 0, MODEM[TXRTSPOL] = 0,
MODEM[TXRTSE] = 0, and MODEM[TXCTSE] = 0.
6. Write to set up interrupt enable fields desired (C3[ORIE], C3[NEIE], C3[PEIE], and
C3[FEIE])
7. Write to set C4[MAEN1] = 0 and C4[MAEN2] = 0.
8. Write to C5 register and configure DMA control register fields as desired for
application.
9. Write to set C7816[INIT] = 1,C7816[ TTYPE] = 0, and C7816[ISO_7816E] = 1.
Program C7816[ONACK] and C7816[ANACK] as desired.
10. Write to IE7816 to set interrupt enable parameters as desired.
11. Write to ET7816 and set as desired.
12. Write to set C2[ILIE] = 0, C2[RE] = 1, C2[TE] = 1, C2[RWU] = 0, and C2[SBK] =
0. Set up interrupt enables C2[TIE], C2[TCIE], and C2[RIE] as desired.
At this time, the UART will start listening for an initial character. After being identified,
it will automatically adjust S2[MSBF], C3[TXINV], and S2[RXINV]. The software must
then receive and process an answer to reset. Upon processing the answer to reset, the
software must write to set C2[RE] = 0 and C2[TE] = 0. The software should then adjust
7816 specific and UART generic parameters to match and configure data that was
received during the answer on reset period. After the new settings have been
programmed, including the new baud rate and C7816[TTYPE], C2[RE] and C2[TE] can
be reenabled as required.
46.8.1.1 Transmission procedure for (C7816[TTYPE] = 0)
When the protocol selected is C7816[TTYPE] = 0, it is assumed that the software has a
prior knowledge of who should be transmitting and receiving. Therefore, no mechanism
is provided for automated transmission/receipt control. The software must monitor
S1[TDRE], or configure for an interrupt, and provide additional data for transmission, as
appropriate. Additionally, software should set C2[TE] = 1 and control TXDIR whenever
it is the UART's turn to transmit information. For ease of monitoring, it is suggested that
only data be transmitted until the next receiver/transmit switchover is loaded into the
transmit FIFO/buffer.
Chapter 46 Universal Asynchronous Receiver/Transmitter (UART)
K22F Sub-Family Reference Manual , Rev. 3, 7/2014
Freescale Semiconductor, Inc.
1209