Information

UARTx_IE7816 field descriptions (continued)
Field Description
0
RXTE
Receive Threshold Exceeded Interrupt Enable
0 The assertion of IS7816[RXT] does not result in the generation of an interrupt.
1 The assertion of IS7816[RXT] results in the generation of an interrupt.
45.3.25 UART 7816 Interrupt Status Register (UARTx_IS7816)
The IS7816 register provides a mechanism to read and clear the interrupt flags. All flags/
interrupts are cleared by writing a 1 to the field location. Writing a 0 has no effect. All
bits are "sticky", meaning they indicate that only the flag condition that occurred since
the last time the bit was cleared, not that the condition currently exists. The status flags
are set regardless of whether the corresponding field in the IC7816 is set or cleared. The
IC7816 controls only if an interrupt is issued to the host processor. This register is
specific to 7816 functionality and the values in this register have no affect on UART
operation and should be ignored if 7816E is not set/enabled. This register may be read or
written at anytime.
Addresses: UART0_IS7816 is 4006_A000h base + 1Ah offset = 4006_A01Ah
UART1_IS7816 is 4006_B000h base + 1Ah offset = 4006_B01Ah
UART2_IS7816 is 4006_C000h base + 1Ah offset = 4006_C01Ah
Bit 7 6 5 4 3 2 1 0
Read
WT CWT BWT INITD
0
GTV TXT RXT
Write
Reset
0 0 0 0 0 0 0 0
UARTx_IS7816 field descriptions
Field Description
7
WT
Wait Timer Interrupt
Indicates that the wait time, the time between the leading edge of a character being transmitted and the
leading edge of the next response character, has exceeded the programmed value. This flag asserts only
when C7816[TTYPE] = 0. This interrupt is cleared by writing 1.
0 Wait time (WT) has not been violated.
1 Wait time (WT) has been violated.
6
CWT
Character Wait Timer Interrupt
Indicates that the character wait time, the time between the leading edges of two consecutive characters
in a block, has exceeded the programmed value. This flag asserts only when C7816[TTYPE] = 1. This
interrupt is cleared by writing 1.
0 Character wait time (CWT) has not been violated.
1 Character wait time (CWT) has been violated.
Table continues on the next page...
Chapter 45 Universal Asynchronous Receiver/Transmitter (UART)
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 1081