UARTx_C1 field descriptions (continued)Field Description0 Normal operation.1 Loop mode where transmitter output is internally connected to receiver input. The receiver input isdetermined by RSRC.6ReservedReserved.This field is reserved.5RSRCReceiver Source SelectThis field has no meaning or effect unless the LOOPS field is set. When LOOPS is set, the RSRC fielddetermines the source for the receiver shift register input.0 Selects internal loop back mode. The receiver input is internally connected to transmitter output.1 Single wire UART mode where the receiver input is connected to the transmit pin input signal.4M9-bit or 8-bit Mode SelectThis field must be set when C7816[ISO_7816E] is set/enabled.0 Normal—start + 8 data bits (MSB/LSB first as determined by MSBF) + stop.1 Use—start + 9 data bits (MSB/LSB first as determined by MSBF) + stop.3WAKEReceiver Wakeup Method SelectDetermines which condition wakes the UART:• Address mark in the most significant bit position of a received data character, or• An idle condition on the receive pin input signal.0 Idle line wakeup.1 Address mark wakeup.2ILTIdle Line Type SelectDetermines when the receiver starts counting logic 1s as idle character bits. The count begins either aftera valid start bit or after the stop bit. If the count begins after the start bit, then a string of logic 1s precedingthe stop bit can cause false recognition of an idle character. Beginning the count after the stop bit avoidsfalse idle character recognition, but requires properly synchronized transmissions.NOTE: • In case the UART is programmed with ILT = 1, a logic of 1'b0 is automatically shifted after areceived stop bit, therefore resetting the idle count.• In case the UART is programmed for IDLE line wakeup (RWU = 1 and WAKE = 0), ILT hasno effect on when the receiver starts counting logic 1s as idle character bits. In idle linewakeup, an idle character is recognized at anytime the receiver sees 10, 11, or 12 1sdepending on the M, PE, and C4[M10] fields.0 Idle character bit count starts after start bit.1 Idle character bit count starts after stop bit.1PEParity EnableEnables the parity function. When parity is enabled, parity function inserts a parity bit in the bit positionimmediately preceding the stop bit. This field must be set when C7816[ISO_7816E] is set/enabled.0 Parity function disabled.1 Parity function enabled.0PTParity TypeTable continues on the next page...Memory map and registersKL27 Sub-Family Reference Manual , Rev. 5, 01/2016684 Freescale Semiconductor, Inc.
