mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 1081

• Manufacturer Part Number: mcf51jf128
• Description: Mcf51jf128 Reference Manual
• Manufacturer: Freescale Semiconductor, Inc

43.3.15 UART FIFO Parameters (UARTx_PFIFO)
This register provides the ability for the programmer to turn on and off FIFO
functionality. It also provides the program with the size of the FIFO that has been
implemented. This register may be read at any time. This register should only be written
when the C2[RE] and C2[TE] bits are cleared / not set and when the data buffer/FIFO is
empty.
Addresses: UART0_PFIFO is FFFF_8140h base + 10h offset = FFFF_8150h
Freescale Semiconductor, Inc.
TXFIFOSIZE
TXFE
Field
Reset
Field
Read
6–4
Write
7
Bit
UART1_PFIFO is FFFF_8160h base + 10h offset = FFFF_8170h
TXFE
0
1
Transmit FIFO Enable
When this bit is set the built in FIFO structure for the transmit buffer is enabled. The size of the FIFO
structure is indicated by the TXFIFOSIZE field. If this bit is not set then the transmit buffer operates as a
FIFO of depth one dataword regardless of the value in TXFIFOSIZE. Both C2[TE] and C2[RE] must be
cleared prior to changing this bit. Additionally TXFLUSH and RXFLUSH commands should be issued
immediately after changing this bit.
0
1
Transmit FIFO. Buffer Depth
The maximum number of transmit datawords that can be stored in the transmit buffer. This field is read
only.
000
001
010
011
100
7
0
CTS has no effect on the transmitter.
Enables clear-to-send operation. The transmitter checks the state of CTS each time it is ready to send
a character. If CTS is asserted, the character is sent. If CTS is deasserted, the signal TXD remains in
the mark state and transmission is delayed until CTS is asserted. Changes in CTS as a character is
being sent do not affect its transmission.
Transmit FIFO is not enabled. Buffer is depth 1. (Legacy support).
Transmit FIFO is enabled. Buffer is depth indicted by TXFIFOSIZE.
Transmit FIFO/Buffer Depth = 1 Dataword.
Transmit FIFO/Buffer Depth = 4 Datawords.
Transmit FIFO/Buffer Depth = 8 Datawords.
Transmit FIFO/Buffer Depth = 16 Datawords.
Transmit FIFO/Buffer Depth = 32 Datawords.
UARTx_MODEM field descriptions (continued)
0
6
MCF51JF128 Reference Manual, Rev. 2, 03/2011
UARTx_PFIFO field descriptions
TXFIFOSIZE
Table continues on the next page...
0
5
Chapter 43 Universal Asynchronous Receiver/Transmitter (UART)
Preliminary
0
4
Description
Description
RXFE
0
3
0
2
RXFIFOSIZE
0
1
0
0
1081