PXR40RM Datasheet, PDF (1222/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

Enhanced Time Processing Unit (eTPU2)
NOTE
It is necessary to turn VIS bit on to set software breakpoints (see the eTPU
Reference Manual for details).
29.3.2.6.2 SCM Low Power
SCM turns off its internal clocks when both Engines are stopped (ETPUECR bit STF asserted), VIS=0 at
ETPUMCR, and MISC is not enabled (SCMMISEN=0). The SCM clocks are automatically turned on if
either one of the STF bits is negated or VIS turns to 1, or SCMMISEN turns to 1.
SCM clocks are not turned off if any of the Engines is not stopped, even if they are both halted.
The conditions for SCM Clocks and MISC activation are summarized in Table 29-16.
Table 29-16. SCM Clocks and MISC activation
ETPUECR_1
STF
ETPUECR_2
STF
ETPUMCR
VIS
ETPUMCR
SCMMISEN
SCM
Clocks
MISC
0
x
0¹
1
On
On
0
x
0¹
0
On
off
x
0
0¹
1
On
On
x
0
0¹
0
On
off
1
1
0
0
off
off
1
1
0
1
On
On
1²
1²
1
0
On
off
1²
1²
1
1
On
off³
0
0
x
0
On
off
0
0
x
1
On
On
1 _{VIS cannot be written 1 if ETPUECR_1 bit STF=0 or ETPUECR_2 bit STF=0, and both HLTF}
bits are 0.
2 _{If VIS=1, neither MDIS can be written 0 nor the Engine leave Stop Mode, regardless of device}
stop reques.
3 _{MISC resets and stays so when VIS=1, restarting automatically when VIS goes 0 if}
SCMMISEN=1.
29.3.2.6.3 SCM Off-range Data
When read accesses are made, either by the Host or by a microengine, to addresses above the limit
corresponding to the SCMSIZE value in ETPUMCR, the value read comes from the register
ETPUSCMOFFDATAR. The Host can program the register at initialization with an opcode value with
operations that try to protect or recover the system from runaway code, for instance: terminate the thread,
clear channel flags, disable match and transition service requests, issue an interrupt, jump to an error
recovery procedure¹. Writes to unimplemented addresses do not return error and can write on unspecified
mirror addresses, so they should be avoided.
1. Only part of these suggested operations can be parallelized in a single instruction. See the eTPU Reference Manual for
details.
29-54
PXR40 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor