Freescale Semiconductor e200z3 Reference Manual page 416

Nexus3/Nexus2+ Module
nex_mseo_b Function
End of variable length packet
Message transmission
Idle (no message)
Figure 10-43 shows the state diagram for single pin MSEO transfers.
Not Allowed
Note that the end message state does not contain valid data on nex_mdo[n:0]. Also, it is not possible to
have two consecutive end packet messages. This implies the minimum packet size for a variable length
packet is 2x the number of nex_mdo[n:0] pins. This ensures that a false end-of-message state is not entered
by emitting two consecutive 1s on nex_mseo_b before the actual end of message.
10-50
Table 10-33. MSEO Pin(s) Protocol (continued)
Single nex_mseo_b data (serial)
0–1–0
0s
1s
nex_mseo_b=1
End
nex_mseo_b=0
Message
MDO: Invalid
nex_mseo_b=1
nex_mseo_b=1
nex_mseo_b=1
End
Packet
nex_mseo_b=0
Figure 10-43. Single-Pin MSEO Transfers
e200z3 Power Architecture Core Reference Manual, Rev. 2
Dual nex_mseo_b[1:0] data
00–01
00s
11s
nex_mseo_b=1
Idle
MDO: Invalid
nex_mseo_b=0
Stage
Message
Normal
Transfer
nex_mseo_b=0
nex_mseo_b=0
Freescale Semiconductor