UART Modules
MCF5253 Reference Manual, Rev. 1
15-4
Freescale Semiconductor
Figure 15-2. External and Internal Interface Signals
15.2.3
Request-To-Send
The Request-To-Send (RTS) pins DDATA3/RTS0/GPIO4 and DDATA1/RTS1/SDATA2_BS2/GPIO2 are
multiplexed. When programmed for RTS, this active-low output signal can be programmed to be
automatically negated and asserted by either the receiver or transmitter. When connected to the
clear-to-send (CTS) input of a transmitter, this signal controls serial data flow.
UART2 has no RTS signal capability.
15.2.4
Clear-To-Send
The multiplexed signals DDATA2/CTS0/GPIO3 and DDATA0/CTS1/SDATA0_SDIO1/GPIO1 can be
programmed as general purpose inputs or Clear-To-Send inputs. When programmed as (CTS), this
active-low input is the clear-to-send input and can generate an interrupt on change-of-state.
UART2 has no CTS signal capability.
15.3
Operation
The following sections describe the operation of the baud-rate generator, transmitter and receiver, and
other operating modes of the UART module.
INTERNAL
CONTROL
LOGIC
Four-character
RECEIVE BUFFER
TWO-CHARACTER
TRANSMIT
INPUT PORT
OUTPUT PORT
EXTERNA
L INTERF
A
C
E SIGNALS
Interf
ace T
o
Cpu
U
A
R
T
MOD
U
LE INTERNAL B
U
S
ADDRESS BUS
CONTROL
DATA
16-BIT TIMER/
BAUD RATE
SYSTEM CLOCK
IRQ
CTS
RTS
RxD
TxD
GENERATOR
BUFFER
Summary of Contents for MCF5253
Page 1: ...Document Number MCF5253RM Rev 1 08 2008 MCF5253 Reference Manual...
Page 26: ...MCF5253 Reference Manual Rev 1 xxvi Freescale Semiconductor...
Page 32: ...MCF5253 Reference Manual Rev 1 xxxii Freescale Semiconductor...
Page 46: ...MCF5253 Introduction MCF5253 Reference Manual Rev 1 1 14 Freescale Semiconductor...
Page 62: ...Signal Description MCF5253 Reference Manual Rev 1 2 16 Freescale Semiconductor...
Page 98: ...Instruction Cache MCF5253 Reference Manual Rev 1 5 10 Freescale Semiconductor...
Page 104: ...Static RAM SRAM MCF5253 Reference Manual Rev 1 6 6 Freescale Semiconductor...
Page 128: ...Synchronous DRAM Controller Module MCF5253 Reference Manual Rev 1 7 24 Freescale Semiconductor...
Page 144: ...Bus Operation MCF5253 Reference Manual Rev 1 8 16 Freescale Semiconductor...
Page 176: ...System Integration Module SIM MCF5253 Reference Manual Rev 1 9 32 Freescale Semiconductor...
Page 198: ...Analog to Digital Converter ADC MCF5253 Reference Manual Rev 1 12 6 Freescale Semiconductor...
Page 246: ...DMA Controller MCF5253 Reference Manual Rev 1 14 18 Freescale Semiconductor...
Page 282: ...UART Modules MCF5253 Reference Manual Rev 1 15 36 Freescale Semiconductor...
Page 344: ...Audio Interface Module AIM MCF5253 Reference Manual Rev 1 17 46 Freescale Semiconductor...
Page 362: ...I2 C Modules MCF5253 Reference Manual Rev 1 18 18 Freescale Semiconductor...
Page 370: ...Boot ROM MCF5253 Reference Manual Rev 1 19 8 Freescale Semiconductor...