mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 1063

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

43.3.1 UART Baud Rate Registers:High (UARTx_BDH)
This register, along with the BDL register, controls the prescale divisor for UART baud
rate generation. To update the 13-bit baud rate setting (SBR[12:0]), first write to BDH to
buffer the high half of the new value and then write to BDL. The working value in BDH
does not change until BDL is written.
BDL is reset to a non-zero value, but after reset the baud rate generator remains disabled
until the first time the receiver or transmitter is enabled (C2[RE] or C2[TE] bits are set).
Addresses: UART0_BDH is FFFF_8140h base + 0h offset = FFFF_8140h
Freescale Semiconductor, Inc.
RXEDGIE
Reserved
LBKDIE
Reset
Field
SBR
Read
4–0
Write
7
6
5
Bit
UART1_BDH is FFFF_8160h base + 0h offset = FFFF_8160h
LBKDIE
LIN Break Detect Interrupt Enable
LBKDIE enables the LIN break detect flag, LBKDIF, to generate interrupt requests based on the state of
LBKDDMAS.
0
1
RxD Input Active Edge Interrupt Enable
RXEDGIE enables the Receive input active edge, RXEDGIF, to generate interrupt requests.
0
1
This read-only bit is reserved and always has the value zero.
UART Baud Rate Bits
The baud rate for the UART is determined by these 13 bits. See
NOTE: The baud rate generator is disabled until the C2[TE] bit or the C2[RE] bit is set for the first time
NOTE: Writing to BDH has no effect without writing to BDL, since writing to BDH puts the data in a
7
0
LBKDIF interrupt requests disabled.
LBKDIF interrupt requests enabled.
Hardware interrupts from RXEDGIF disabled (use polling).
RXEDGIF interrupt request enabled.
after reset.The baud rate generator is disabled when SBR = 0.
temporary location until BDL is written.
RXEDGIE
0
6
MCF51JF128 Reference Manual, Rev. 2, 03/2011
UARTx_BDH field descriptions
0
0
5
Chapter 43 Universal Asynchronous Receiver/Transmitter (UART)
Preliminary
0
4
Description
0
3
Baud rate generation
SBR
0
2
0
1
for details.
0
0
1063