NXP Semiconductors
UM191812
PN544 C2 User Manual
191812
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© NXP B.V. 2010. All rights reserved.
User Manual
Rev. 1.2 — 2010-06-16
60 of 172
9.4.2.2 Clock Request using HCI Event
The following figures show the 2 possible use of HCI Event for Clock Request &
acknowledge:
1
3
2
(1)
Fig 34. Clock request with HCI Event, acknowledge with HCI Event
1
3
2
(1)
Fig 35. Clock request with HCI Event, acknowledge with Timeout
Note:
Step2
means that system clock is stable and available for PN544.
9.4.3 Clock Request & Release
There are 3 ways to setup the clock request.
WARNING:
Clock request/acknowledge mechanism is not available with HSU link.
When PN544 is in HSU mode, the ‘No clock request’ setup must be chosen. HSU
mode imposes System clock always present.