Uart 7816 Wait Fd Register (Uartx_Wf7816); Uart 7816 Error Threshold Register (Uartx_Et7816) - NXP Semiconductors MKL27Z128VFM4 Reference Manual

Table of Contents

Memory map and registers

38.4.18 UART 7816 Wait FD Register (UARTx_WF7816)

The WF7816 contains parameters that are used in the generation of various counters

including GT, CGT, BGT, WT, and BWT. This register may be read at any time. This

Address: 4006_C000h base + 1Dh offset = 4006_C01Dh

FD Multiplier

Used as another multiplier in the calculation of BWT. This value represents a number between 1 and 255.

The value of 0 is invalid. This value is not used in baud rate generation. See

The ET7816 register contains fields that determine the number of NACKs that must be

received or transmitted before the host processor is notified. This register may be read at

anytime. This register must be written to only when C7816[ISO_7816E] is not set.

Address: 4006_C000h base + 1Eh offset = 4006_C01Eh

Transmit NACK Threshold

The value written to this field indicates the maximum number of failed attempts (NACKs) a transmitted

character can have before the host processor is notified. This field is meaningful only when

C7816[TTYPE] = 0 and C7816[ANACK] = 1. The value read from this field represents the number of

consecutive NACKs that have been received since the last successful transmission. This counter

saturates at 4'hF and does not wrap around. Regardless of how many NACKs that are received, the

UART continues to retransmit indefinitely. This flag only asserts when C7816[TTYPE] = 0. For additional

information see the IS7816[TXT] field description.

TXT asserts on the first NACK that is received.

TXT asserts on the second NACK that is received.

UARTx_WF7816 field descriptions

Baud rate generation

UARTx_ET7816 field descriptions

Table continues on the next page...

KL27 Sub-Family Reference Manual , Rev. 5, 01/2016

Wait time and guard time

Freescale Semiconductor, Inc.