MPC555CME Freescale Semiconductor, MPC555CME Datasheet - Page 727

• Manufacturer Part Number: MPC555CME
• Description: KIT EVALUATION FOR MPC555
• Manufacturer: Freescale Semiconductor
• Type: Microcontrollerr

Specifications of MPC555CME

• Contents: Module Board, Installation Guide, Power Supply, Cable, Software and more
• Processor To Be Evaluated: MPC555
• Data Bus Width: 32 bit
• Interface Type: RS-232
• For Use With/related Products: MPC555
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

21.5 Development Port
21.5.1 Development Port Pins
21.5.2 Development Serial Clock
21.5.3 Development Serial Data In
MPC555
USER’S MANUAL
performing the rfi. Failing to do so will force the CPU to immediately re-enter to debug
mode and to re-assert the freeze indication in case an asserted bit in the interrupt
cause register (ECR) has a corresponding enable bit set in the debug enable register
(DER).
The development port provides a full duplex serial interface for communications be-
tween the internal development support logic including debug mode and an external
development tool.
The relationship of the development support logic to the rest of the CPU chip is shown
in
clarity. It is implemented as part of the SIU module.
The following development port pin functions are provided:
The development serial clock (DSCK) is used to shift data into and out of the develop-
ment port shift register. At the same time, the new most significant bit of the shift reg-
ister is presented at the DSDO pin. In all further discussions references to the DSCK
signal imply the internal synchronized value of the clock. The DSCK input must be driv-
en either high or low at all times and not allowed to float. A typical target environment
would pull this input low with a resistor.
The clock may be implemented as a free running clock or as gated clock. As discussed
in section
Mode
Mode, the shifting of data is controlled by ready and start signals so the clock does not
need to be gated with the serial transmissions.
The DSCK pin is also used at reset to enable debug mode and immediately following
reset to optionally cause immediate entry into debug mode following reset.
Data to be transferred into the development port shift register is presented at the de-
velopment serial data in (DSDI) pin by external logic. To be sure that the correct value
is used internally. When driven asynchronous (synchronous) with the system clock,
the data presented to DSDI must be stable a setup time before the rising edge of
DSCK (CLKOUT) and a hold time after the rising edge of DSCK (CLKOUT).
Figure
1. Development serial clock (DSCK)
2. Development serial data in (DSDI)
3. Development serial data out (DSDO)
/
MPC556
and section
21-5. The development port support logic is shown as a separate block for
21.5.6.5 Development Port Serial Communications — Trap Enable
21.5.6.8 Development Port Serial Communications — Debug
DEVELOPMENT SUPPORT
Rev. 15 October 2000
MOTOROLA
21-31