24-22
MPC561/MPC563 Reference Manual
MOTOROLA
Signal Interface
24.7.1.1 Signals Implemented
The READI module implements one MCKO, MCKI, EVTI, RSTI, MSEO, and MSEI
signal. It also implements one or two MDI and two or eight MDO signals. The input signals
are synchronized to the MCKI input clock and the output signals are synchronized to the
free running MCKO output clock. The MCKI input clock should be synchronised to the
MCKO ouput clock to ensure correct message reception. The READI signal definition is
NOTE
MCKI clock frequency has to be less than or equal to one half
of MCKO clock frequency.
24.7.2
Functional Block Diagram
Figure 24-11 depicts the functional block diagram of the signal interface.
Table 24-17. Description of READI Signals
IEEE-ISTO
5001 Signal
Name
Input/
Output
Description of Signal
MCKO
Output
Message Clock-Out (MCKO) is a free-running output clock to development tools for timing of
MDO and MSEO signal functions. MCKO is the same as the MCU system clock.
MDO[7:0] or
MDO[1:0]
Output
Message Data Out (MDO[7:0] or MDO[1:0]) are output signals used for uploading OTM, BTM,
DTM, and Read/Write Accesses. External latching of MDO will occur on rising edge of MCKO.
Eight signals are implemented. MDO[7:0] are used in full port mode, MDO[1:0] are used in
reduced port mode.
MSEO
Output
Message Start/End Out (MSEO) is an output signal which indicates when a message on the
MDO signals has started, when a variable length packet has ended, and when the message
has ended. 1 MSEO signal is implemented. External latching of MSEO will occur on rising
edge of MCKO.
MCKI
Input
Message Clock-In (MCKI) is a input clock from development tools for timing of MDI and MSEI
signal functions. MCKI frequency has to be less than or equal to one half of MCKO frequency.
MDI[1:0]
or
MDI0
Input
Message Data In (MDI[1:0] or MDI[0]) are input signals used for downloading configuration
information, writes to user resources, etc. Internal latching of MDI will occur on rising edge of
MCKI. Two signals are implemented on the MPC561/MPC563. MDI[1:0] are used in full port
mode, MDI[0] only is used in reduced port mode.
MSEI
Input
Message Start/End In (MSEI) is an input signal which indicates when a message on the MDI
signals has started, when a variable length packet has ended, and when the message has
ended. 1 MSEI signal is implemented. Internal latching of MSEI will occur on rising edge of
MCKI.
EVTI
Input
Event In (EVTI) — The EVTI signal is level sensitive when configured for breakpoint
generation, otherwise it is edge sensitive.
RSTI
Input
Reset In (RSTI).