MSC8144E Reference Manual, Rev. 3
20-2
Freescale
Semiconductor
UART
As Figure 20-2 shows, the UART allows full duplex, asynchronous, non-return-to-zero (NRZ)
serial communication between the MSC8144E and remote devices, including other MSC8144E
devices. The UART transmitter and receiver operate independently, although they use the same
baud-rate generator and same character length. An SC3400 core monitors the status of the
UART, writes the data to be transmitted, and processes received data.
Figure 20-3 shows the full duplex UART system in which the MSC8144E UART transmits and
receives simultaneously. A higher-level protocol should handle the full duplex communication to
guarantee that no more than one target UART transmits to the
URXD
signal of the initiator at a
given time. Receiver wake-up can obtain such a protocol (see Section 21.2.7, Receiver
Wake-Up). The UART
UTXD
signal can be configured with full CMOS drive or with open-drain
drive (see Chapter 22, GPIO). In both cases, the external pull-up resistor is needed to avoid
floating input at the
URXD
of the initiator.
Figure 20-2. UART Block Diagram
SCI Data
Receive
Shift Register
SCI Data
Register
Transmit
Shift Register
Register
Baud-Rate
Generator
SBR[12–0]
URXD
UTXD
Sy
s
tem
Transmit
Control
³16
Receive
and Wake-Up
Data Format
Control
Control
T8
PF
FE
NF
RDRF
IDLE
TIE
OR
TCIE
TDRE
TC
R8
RAF
RWU
RE
PE
ILT
PT
WAKE
M
Cl
o
c
k
UART
ILIE
RIE
Interrupt
SBK
TE
Request
Loop
LOOPS
RSRC
Control
UTXD
From
Transmitter
R[7–0]
T[7–0]
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...