Information

45.3.23 UART 7816 Control Register (UARTx_C7816)
The C7816 register is the primary control register for ISO-7816 specific functionality.
This register is specific to 7816 functionality and the values in this register have no effect
on UART operation and should be ignored if ISO_7816E is not set/enabled. This register
may be read at anytime but values should only be changed when the ISO_7816E bit is not
set.
Addresses: UART0_C7816 is 4006_A000h base + 18h offset = 4006_A018h
UART1_C7816 is 4006_B000h base + 18h offset = 4006_B018h
UART2_C7816 is 4006_C000h base + 18h offset = 4006_C018h
UART3_C7816 is 4006_D000h base + 18h offset = 4006_D018h
UART4_C7816 is 400E_A000h base + 18h offset = 400E_A018h
UART5_C7816 is 400E_B000h base + 18h offset = 400E_B018h
Bit 7 6 5 4 3 2 1 0
Read 0
ONACK ANACK INIT TTYPE
ISO_7816E
Write
Reset
0 0 0 0 0 0 0 0
UARTx_C7816 field descriptions
Field Description
7–5
Reserved
This read-only field is reserved and always has the value zero.
4
ONACK
Generate NACK on Overflow
When this bit is set, the receiver will automatically generate a NACK response if a receive buffer overrun
occurs as indicated by the S1[OR] field. In many systems this will result in the transmitter resending the
packet that overflowed until the retransmit threshold for that transmitter has been reached. A NACK is
only generated if TTYPE=0. This bit operates independently of ANACK. See Overrun NACK
considerations.
0 The received data does not generate a NACK when the receipt of the data results in an overflow
event.
1 If the receiver buffer overflows, a NACK is automatically sent on a received character.
3
ANACK
Generate NACK on Error
When this bit is set, the receiver will automatically generate a NACK response if a parity error occurs or if
INIT is set and an invalid initial character is detected. A NACK is only generated if TTYPE = 0. If ANACK
is set the UART will attempt to retransmit the data indefinitely. To stop retransmission attempts, clear
C2[TE] or ISO_7816E and do not set until S1[TC] set C2[TE] again.
0 No NACK is automatically generated.
1 A NACK is automatically generated if a parity error is detected or if an invalid initial character is
detected.
2
INIT
Detect Initial Character
Table continues on the next page...
Memory map and registers
K10 Sub-Family Reference Manual, Rev. 6, Nov 2011
1288 Freescale Semiconductor, Inc.