UARTx_C7816 field descriptions (continued)Field Description0 No NACK is automatically generated.1 A NACK is automatically generated if a parity error is detected or if an invalid initial character isdetected.2INITDetect Initial CharacterWhen this field is set, all received characters are searched for a valid initial character. If an invalid initialcharacter is identified, and ANACK is set, a NACK is sent. All received data is discarded and error flagsblocked (S1[NF], S1[OR], S1[FE], S1[PF], IS7816[WT], IS7816[CWT], IS7816[BWT], IS7816[ADT],IS7816[GTV]) until a valid initial character is detected. Upon detecting a valid initial character, theconfiguration values S2[MSBF], C3[TXINV], and S2[RXINV] are automatically updated to reflect the initialcharacter that was received. The actual INIT data value is not stored in the receive buffer. Additionally,upon detection of a valid initial character, IS7816[INITD] is set and an interrupt issued as programmed byIE7816[INITDE]. When a valid initial character is detected, INIT is automatically cleared. This InitialCharacter Detect feature is supported only in T = 0 protocol mode.0 Normal operating mode. Receiver does not seek to identify initial character.1 Receiver searches for initial character.1TTYPETransfer TypeIndicates the transfer protocol being used.See ISO-7816 / smartcard support for more details.0 T = 0 per the ISO-7816 specification.1 T = 1 per the ISO-7816 specification.0ISO_7816EISO-7816 Functionality EnabledIndicates that the UART is operating according to the ISO-7816 protocol.NOTE: This field must be modified only when no transmit or receive is occurring. If this field is changedduring a data transfer, the data being transmitted or received may be transferred incorrectly.0 ISO-7816 functionality is turned off/not enabled.1 ISO-7816 functionality is turned on/enabled.38.4.14 UART 7816 Interrupt Enable Register (UARTx_IE7816)The IE7816 register controls which flags result in an interrupt being issued. This registeris specific to 7816 functionality, the corresponding flags that drive the interrupts are notasserted when 7816E is not set/enabled. However, these flags may remain set if they areasserted while 7816E was set and not subsequently cleared. This register may be read orwritten to at any time.Address: 4006_C000h base + 19h offset = 4006_C019hBit 7 6 5 4 3 2 1 0Read WTE CWTE BWTE INITDE ADTE GTVE TXTE RXTEWriteReset 0 0 0 0 0 0 0 0Chapter 38 Universal Asynchronous Receiver/Transmitter(UART)KL27 Sub-Family Reference Manual , Rev. 5, 01/2016Freescale Semiconductor, Inc. 697
