MPC563XM Reference Manual, Rev. 1
810
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
Channel Selection Register - CHAN
CHAN is the register that holds the number of the channel that qualifies the context of most Channel
Registers, including Pin Control and ER accesses, and is common to all channels in a same Engine.
When a thread starts to be executed, the contents of CHAN register is automatically updated on Time Slot
transition to the number of the channel to be serviced. Serviced channel is constant during channel
servicing, but the selected channel can be changed any time by microengine writing into CHAN register.
Some microinstructions are affected by the serviced channel instead of CHAN. These are:
•
Conditional branch using LSR (see
Section 23.4.8.1.6, “LINK Register
”) or Function Mode
(
Section 23.3.7.2, “ETPUCxSCR - eTPU Channel x Status Control Register
”).
•
Negate channel flag LSR, Interrupt CPU and Data Transfer Request (see
“Channel Interrupt and Data Transfer Requests
When CHAN register is written, accesses are qualified by the new CHAN register value from the
instruction following CHAN assignment on, except Capture 1/2 sampling into ERT1/2 and Match register
writing from ERT1/2 (see
Section 23.4.9.6.5, “CHAN assignment, Read Match and ERW1/2
Writing CHAN (including with the same value, CHAN:= CHAN) updates ERT1 and ERT2 with the new
captured values, the branch logic with updated MRL1/2 and TDL1/2 flags.
shows the commands, flags and registers selected by the CHAN register value
Table 23-27. General Channel registers microcode access
Register
Access Type
Sampled
from
channel
Update to
channel
Microcode
fields
1
1
See
Section 23.4.9, “Microinstruction Set
.”
Reset
value
CHAN
read/write
n.a.
2
2
CHAN is common to all channels in the Engine.
n.a.
T4ABS,
T4BBS,
T2ABD
defaults to serviced
channel at thread start
PDCM
write only
no
immediate
PDCM
1100
(sm_st)
UDCM
write only
no
from ERT1 by
microcode
CMW,
ERW1
parameter value defined at
integration
3
3
See the eTPU Integration Guide for parameter details and default value.
SRI
write only
no
immediate
MTD
1
Flag1,Flag0
branch flag test,
write
no
immediate
BCC,FLC
0, 0
Table 23-28. CHAN-selected features
Feature Used
Selected by
CHAN
channel-relative SPRAM access
YES