ks8701 Samsung Semiconductor, Inc., ks8701 Datasheet - Page 67

• Manufacturer Part Number: ks8701
• Description: Flextm Roaming Decoder Ii
• Manufacturer: Samsung Semiconductor, Inc.

Appendix A: Application Notes
USING THE RECEIVER SHUTDOWN PACKET
CALCULATING TIME LEFT
implementing a roaming algorithm.
asynchronous mode.
66
The receiver shutdown packet gives timing information to the host. Two times are of particular interest when
l
l
Where,
The formula’ s for calculating these times depend on whether the KS8701 is in synchronous mode or
SYNCHRONOUS MODE:
ASYNCHRONOUS MODE:
Time To Warm Up Start. Defined as the amount of time there is before the receiver will start to warm up
(i.e. transition from the off state to the first warm up state).
Time To Tasks Disabled. Defined as the amount of time the host has to complete any host initiated tasks
(e.g. by setting SND or SAS in the roaming control packet).
Time To Warm Up Start ¯ (TNF • 80ms) + (Skipped Frames • 1874.375ms) + Receiver Off Time
Time To Tasks Disabled ¯ (TNF • 80ms) + (Skipped Frames • 1874.375ms)
Time To Warm Up Start ¯ ((TNF - 2) • 80ms) + Receiver Off Time
Time To Tasks Disabled ¯ ((TNF - 3) • 80ms)
TNF:
Skipped Frames:
Receiver Off Time: The time programmed in the receiver off setting packet.
The number of frames that won’ t be decoded. This can be calculated from the
Time to Next Frame. Value from the receiver shutdown packet.
Current Frame (CF) and Next Needed Frame (NAF) fields in the receiver shutdown
packet (e.g. If CF is 10 and NAF is 12, then Skipped Frames is 1)
FLEX
TM
Roaming Decoder II
-
247.5ms
-
167.5ms
KS8701