NXP Semiconductors MPC5644A, Reference Manual, Page: 809 / 1735

Enhanced Time Processing Unit (eTPU2)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 809
24.4.7.3 ETPU_CxHSRR – eTPU Channel x Host Service Request Register
ETPU_CxHSRR is used by the Host to issue service requests to the channel.
Figure 24-23. ETPU_CxHSRR Register
Offset: Channel_Registe 0x8 Access: User read/write
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
R 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
R 0 0 0 0 0 0 0 0 0 0 0 0 0 HSR
W
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
= Unimplemented or Reserved
Table 24-35. ETPU_CxHSRR field description
Field Description
0-28 Reserved
29-31 HSR[2:0]—Host Service Request
This field is used by the Host CPU to request service to the channel (see
Section 24.5.2.5, Host service
requests ).
HSR = 000: no Host Service Request pending
HSR > 000: function-dependent Host Service Request pending.
HSR value turns to 000 automatically at the end of microengine service for that channel, but only if the
thread started due to an HSR. Host should write HSR > 0 only when HSR = 0. Writing HSR = 000
withdraws a pending request if scheduler did not begin to resolve the Entry Point yet, but it does not abort
the service thread from that point on. For more details, see
Section 24.5.1.1, Entry points , and
Section 24.5.2.5, Host service requests .