DMA2275 MICRONAS [Micronas], DMA2275 Datasheet - Page 5

• Manufacturer Part Number: DMA2275
• Description: DMA 2275, DMA 2286 C/D/D2-MAC Descrambler
• Manufacturer: MICRONAS [Micronas]

2. Chip Architecture
Figure 2–1 shows the architecture of the descrambling
chip DMA 2286. The DMA 2275 architecture is identical
to the that of the DMA 2286, except that the sound pro-
cessor is missing. The chips can be subdivided into sev-
eral functional blocks.
DMA 2275 and DMA 2286:
Video Processor
– descrambling, panning and interpolation of the video
PRBS Generator
– delivers cut points and cipher streams
Line 625 Processor
– acquisition of service identification data and real time
Baseband
Vdd
Vdd
GND
GND
Fig. 2–1: Block diagram of the DMA 2286
signal
control information
8
Interface Processor
8
Code
Converter
DRAM
Interface
8
Video
Descrambler
3
Video
PRBS
Generator
Fast
Processor
IM Bus
Interface
8
Timing
Generator
Interpolation
Filter
Timing
Generator
PRBS Generator
Packet Processor
– acquisition of entitlement packets, acquisition of gen-
Interface Processor
– management of internal and external data transfer
Timing Generator
– delivers internal chip timing
DMA 2286 only:
Sound Processor
– spectrum descrambling of data burst, packet deinter-
eral purpose packets, selection of cipher stream, des-
crambling of data packets
leaving (one subframe only), sound packet processing
(one subframe only)
8
8
Line 625 Proc.
Packet Processor
Clamping +
Video Gate
Packet
Acquisition
Line 625
Acquisition
DMA 2275, DMA 2286
8
Video Processor
12
Spectr. Descr.
Deinterleaver
Packet
Descrambler
Sound
Processing
Packet
PRBS
Generator
2
Sound
Proc.
Baseband
VBI
Data
Corrected
Packet
Data
Descrambl.
Packet
Data
Packet
Data
Burst
Data
5