DSP56303 FREESCALE [Freescale Semiconductor, Inc], DSP56303 Datasheet - Page 23

• Manufacturer Part Number: DSP56303
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

1.9.4 SCI
The SCI provides a full-duplex port for serial communication with other DSPs, microprocessors,
or peripherals such as modems. The SCI interfaces without additional logic to peripherals that
use TTL-level signals. With a small amount of additional logic, the SCI can connect to peripheral
interfaces that have non-TTL level signals, such as the RS-232C, RS-422, etc. This interface uses
three dedicated signals: transmit data, receive data, and SCI serial clock. It supports
industry-standard asynchronous bit rates and protocols, as well as high-speed synchronous data
transmission (up to 12.5 Mbps for a 100 MHz clock). SCI asynchronous protocols include a
multidrop mode for master/slave operation with wakeup on idle line and wakeup on address bit
capability. This mode allows the DSP56303 to share a single serial line efficiently with other
peripherals.
Separate SCI transmit and receive sections can operate asynchronously with respect to each
other. A programmable baud-rate generator provides the transmit and receive clocks. An enable
vector and an interrupt vector allow the baud-rate generator to function as a general-purpose
timer when the SCI is not using it or when the interrupt timing is the same as that used by the
SCI.
1.9.5 Timer Module
The triple timer module is composed of a common 21-bit prescaler and three independent and
identical general-purpose 24-bit timer/event counters, each with its own memory-mapped
register set. Each timer has the following properties:
Freescale Semiconductor
Network mode operation with as many as 32 time slots
Programmable word length (8, 12, or 16 bits)
Program options for frame synchronization and clock generation
One receiver and three transmitters per ESSI
A single signal that can function as a GPIO signal or as a timer signal
Uses internal or external clocking and can interrupt the DSP after a specified number of
events (clocks) or signal an external device after counting internal events
Connection to the external world through one bidirectional signal. When this signal is
configured as an input, the timer functions as an external event counter or measures
external pulse width/signal period. When the signal is used as an output, the timer
functions as either a timer, a watchdog, or a pulse width modulator.
DSP56303 User’s Manual, Rev. 2
Peripherals
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