Datasheet
Chapter 17. Signal Descriptions 17-19
Timer Module Signals
17.9.2 Receiver Serial Data Input (RxD)
Data received on RxD is sampled on the rising edge of the clock source, with the lsb
received first. For UART1 in modem mode, data received on RxD is sampled on the falling
edge of the clock signal driving UART1’s CTS
input. UART1 transfers can be specified as
either lsb or msb first.
17.9.3 Clear to Send (CTS)
This input can generate an interrupt on a change of state. For UART1 in modem mode, CTS
must be driven by the serial bit clock from the external CODEC or AC97 controller.
17.9.4 Request to Send (RTS)
This output can be programmed to be negated or asserted automatically by either the
receiver or the transmitter. When connected to a transmitter’s CTS
, RTS can control serial
data fl ow. For UART1 in AC97 mode, R
TS serves as the frame sync or start of frame (SOF),
output to the external AC97 controller. When this mode is used, the AC97 BIT_CLK, which
is input on CTS
, is divided by 256.
17.10 Timer Module Signals
The signals in the following sections are external interfaces to the two general-purpose
MCF5407 timers. These 16-bit timers can capture timer values, trigger external events or
internal interrupts, or count external events.
17.10.1 Timer Inputs (TIN[1:0])
TIN[1:0] can be programmed as clocks that cause events in the counter and prescalers.
They can also cause captures on the rising edge, falling edge, or both edges.
17.10.2 Timer Outputs (TOUT1, TOUT0)
The programmable timer outputs (TOUT1 and TOUT0) pulse or toggle on various timer
events.
17.11 Parallel I/O Port (PP[15:0])
This 16-bit bus is dedicated for general-purpose I/O. The parallel port is multiplexed with
the A[31:24], TT[1:0], TM[2:0], TIP
, and DREQ[1:0]. These 16 bits are programmed for
functionality with the PAR in the SIM.
The system designer controls the reset value of this register by driving D4 with a 1 or 0 on
the rising edge of RSTI
(reset input to MCF5407 device). At reset, the system is configured
as PP[15:0] if D4 is 0; otherwise alternate pin functions selected by PAR = 1 are used.