
UART Modules
Freescale Semiconductor
31-19
optional parity bit, and the programmed number of stop bits. The lsb is sent first. Data is shifted from the
transmitter output on the falling edge of the clock source.
After the stop bits are sent, if no new character is in the transmitter holding register, the U
n
TXD output
remains high (mark condition) and the transmitter empty bit (USR
n
[TXEMP]) is set. Transmission
resumes and TXEMP is cleared when the CPU loads a new character into the UART transmit buffer
(UTB
n
). If the transmitter receives a disable command, it continues until any character in the transmitter
shift register is completely sent.
If the transmitter is reset through a software command, operation stops immediately (see
“UART Command Registers (UCRn)
”). The transmitter is reenabled through the UCR
n
to resume
operation after a disable or software reset.
If the clear-to-send operation is enabled, U
n
CTS must be asserted for the character to be transmitted. If
U
n
CTS is negated in the middle of a transmission, the character in the shift register is sent and U
n
TXD
remains in mark state until U
n
CTS is reasserted. If transmitter is forced to send a continuous low condition
by issuing a
SEND
BREAK
command, transmitter ignores the state of U
n
CTS.
If the transmitter is programmed to automatically negate U
n
RTS when a message transmission completes,
U
n
RTS must be asserted manually before a message is sent. In applications in which the transmitter is
disabled after transmission is complete and U
n
RTS is appropriately programmed, U
n
RTS is negated one
bit time after the character in the shift register is completely transmitted. The transmitter must be manually
reenabled by reasserting U
n
RTS before the next message is sent.
shows the functional timing information for the transmitter.
MCF5329 Reference Manual, Rev 3
Summary of Contents for MCF5329
Page 106: ...ColdFire Core 3 32 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 148: ...Cache 5 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 154: ...Static RAM SRAM 6 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 184: ...Power Management 8 18 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 204: ...Reset Controller Module 10 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 220: ...System Control Module SCM 11 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 228: ...Crossbar Switch XBS 12 8 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 268: ...General Purpose I O Module 13 40 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 392: ...SDRAM Controller SDRAMC 18 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 436: ...Fast Ethernet Controller FEC 19 44 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 594: ...FlexCAN 23 30 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 678: ...Pulse Width Modulation PWM Module 26 22 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 684: ...Watchdog Timer Module 27 6 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 704: ...DMA Timers DTIM0 DTIM3 29 12 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 754: ...UART Modules 31 34 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 770: ...I2 C Interface 32 16 Freescale Semiconductor MCF5329 Reference Manual Rev 3...
Page 866: ...Debug Module 36 50 Freescale Semiconductor MCF5329 Reference Manual Rev 3...