Information

UARTx_IE7816 field descriptions (continued)
Field Description
0
RXTE
Receive Threshold Exceeded Interrupt Enable
0 The assertion of the IS7816[RXT] bit will not result in the generation of an interrupt.
1 The assertion of the IS7816[RXT] bit will result in the generation of an interrupt.
48.3.25 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 bit location. Writing a "0" has no effect. All
bits are "sticky", meaning they only indicate that the flag condition occurred since the last
time the bit was cleared not that the condition currently exists. The status flags are set
regardless of if the corresponding bit in the IC7816 is set or cleared, the IC7816 only
controls if a 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
UART3_IS7816 is 4006_D000h base + 1Ah offset = 4006_D01Ah
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
This flag 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 programed value. This flag only
asserts 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
This flag indicates that the character wait time, the time between the leading edges of two consecutive
characters in a block has exceed the programed value. This flag only asserts 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 48 Universal Asynchronous Receiver/Transmitter (UART)
K20 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc. 1329