MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
20-1
UART
20
The UART, also known as the serial communication interface (SCI), is a full-duplex port for
serial communications with other devices. This interface uses two dedicated signals: transmit
data (
UTXD
) and receive data (
URXD
) (see Figure 20-1). The external connections shared by these
signals with
GPIO[14,20]
are available as general-purpose I/O (GPIO) signals when they are not
configured for UART operation (see Chapter 22, GPIO for details).
The UART is accessible, via the MBus, to an external host or to each of the SC3400 cores. The
UART generates one interrupt signal that connects to each SC3400 core so that each SC3400
core can service UART interrupts. For details on UART interrupt signal connectivity, refer to
Chapter 17, Interrupt Processing. When accepting an interrupt request, an SC3400 core or
external host should read the UART status register (SCISR) to identify the interrupt source and
service it accordingly. During reception, the UART generates an interrupt request when a new
character is available to the UART data register, SCI Data Register (SCIDR). An SC3400 core or
external host then reads the character from the data register. During transmission, the UART
generates an interrupt request when its data register can be written with new character. An
SC3400 core or external host then writes the character to the data register.
Figure 20-1. UART Interface
SCI
URXD
UTXD
UART
Interrupt
Request
MBus
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 ...