Freescale Semiconductor MPC5200B User Manual page 556

PSC
IPB Clock
IPB
Interface
CommBus
Interface
IRQ
Controller
BestComm
Request
An internal interrupt request signal (IRQ) is provided to notify the Interrupt Controller of an interrupt condition. The output is the logical NOR
of unmasked ISR bits. The interrupt level of a PSC module is programmed in the Interrupt Controller in the system integration module:
Chapter 7, System Integration Unit
The PSC can automatically transfer data using the BestComm, rather than interrupting the core. When IMR[FFULL] is 1 and Rx FIFO is full,
it can send an interrupt to a BestComm channel so the FIFO data can be transferred to memory.
Table 15-75 briefly describes the PSC module signals.
The terms "assertion" and "negation" are used to avoid confusion between active-low and active-high
signals.
– Asserted indicates a signal is active, independent of the voltage level
– Negated indicates a signal is inactive.
Signal
TxD Transmitter Serial Data Output—TxD is held high (mark condition) when Tx is disabled, idle, or operating
in the local loop-back mode. Data is shifted out on TxD on the falling edge of the clock source, with the least
significant bit (lsb) sent first.
RxD Receiver Serial Data Input—Data received on RxD is sampled on the rising edge of the clock source, with
the lsb received first.
CTS Clear-to-Send—This input can generate an interrupt on a change of state.
RTS Request-to-Send—This output can be programmed to be negated or asserted automatically by either Rx
or Tx. When connected to a transmitter CTS, RTS can control serial data flow.
DCD Data carrier detect Input — In the enhanced UART mode this signal must be assert during the data
transmission.
Freescale Semiconductor
Clock
Generation Unit
CSR
{CTUR:CTLR}
Rx FIFO
Tx FIFO
Figure 1-1PSC UART Block Diagram
(SIU). The PSC uses the autovector for the programmed interrupt level.
NOTE
Table 15-75. PSC Signal Description for UART Mode
MPC5200B Users Guide, Rev. 1
Port
Control
Logic
Receiver
TxD
Transmitter
Description
PSC Operation Modes
DCD
RTS
CTS
External
Interface
RxD Signals
15-45