Freescale Semiconductor MPC5553 - Auxiliary Output Port

MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
25-18 Freescale Semiconductor
25.7.2 Auxiliary Output Port
The auxiliary output port is shared by each of the Nexus modules on the device. The NPC communicates
with each of the individual modules and arbitrates for access to the port. Additional information about the
auxiliary port is found in Section 25.2, “External Signal Description.”
25.7.2.1 Output Message Protocol
The protocol for transmitting messages via the auxiliary port is accomplished with the MSEO functions.
The MSEO pins are used to signal the end of variable-length packets and the end of messages. They are
not required to indicate the end of fixed-length packets. MDO and MSEO are sampled on the rising edge
of MCKO.
Figure 25-5 illustrates the state diagram for MSEO transfers. All transitions not included in the figure are
reserved, and must not be used.
Figure 25-5. MSEO Transfers
Yes 1 1 Full-Port Mode
Yes 1 0 Reduced-Port Mode
Table 25-12. NPC Reset Configuration Options (Continued)
JCOMP Asserted? PCR[MCKO_EN] PCR[FPM]
Configuration
MSEO = 00
MSEO = 11
MSEO = 01
MSEO = 00
Normal
Transfer
End
Packet
Start
Message
End
Message
Idle
MSEO = 00MSEO = 01 MSEO = 11
M
S
E
O
=
0
1
M
S
E
O
=
1
1
M
S
E
O
=
0
0
M
S
E
O
=
1
0
M
S
EO
=
1
1
MSEO = 01 MSEO = 00
MSEO = 10
MSEO = 01
MSEO = 11
MDO:
Invalid
MDO:
Invalid
MSEO = 10