DMA2286 datasheet(12/48 Pages) MICRONAS

12 / 48 page

DMA 2275, DMA 2286

8. Interface Processor

The interface processor consists of:

– Fast Processor

– IM Bus Interface

– DRAM Interface

8.1. Fast Processor

The fast processor (FP) is a RISC–type 12 bit microcon-

troller built in CMOS technology. The maximum clock

frequency of 40 MHz and the internal architecture that

allows parallel ALU operation and data transfer to or

from internal RAM, make it applicable for very high

speed tasks, such as control and parameter calculation

in digital signal processors.

The FP is embedded in the DMA 2275 or DMA 2286 with

256 x 12 bit RAM and 2K x 20 bit ROM and runs with

20.25 MHz. The FP performs the following tasks:

– data transfer to and from DRAM interface

– data transfer to and from IM Bus interfaces

– support of packet acquisition

– support of line 625 acquisition

– initialization of PRBS generators

– control of video descrambler

– control of interpolation filter

Fig. 8–1 shows roughly when the different FP tasks are

executed within a frame period.

In normal operation the FP will not be directly accessed

from outside, that means that the CCU software will not

see another processor on the descrambling chip but

only a set of registers and buffers which are located ei-

ther in the acquisition DRAM or in the FP internal

memory. The CCU can access both memories via IM

Bus.

Changing any register in the DRAM memory by CCU

software will not effect the descrambler hardware im-

mediately. The FP will read or update the DRAM

memory only on frame boundaries, i.e. from line 622 to

line 7 inclusive. Changing registers in the FP memory by

CCU software will effect the descrambler hardware im-

mediately.

line_sync

prbs2

manager

line_625_store

line_sync

prbs2

manager

vcw_update

pab_update

line_sync

prbs2

manager

dcw1_update

dcw2_update

line_sync

prbs2

manager

dcw3_update

dcw4_update

line_sync

prbs2

manager

cw_conversion

line_sync

prbs2

manager

psc_update

line_sync

prbs2

manager

prbs_init

prbs2_init

enable_imbus

enable_packet_sync

line_sync

prbs2

packet acquisition

imbus

packet_sync

packet_read

pae_comparator

buffer_manager

packet_link

packet_store

packet_error

line_sync

prbs2

manager

pae_low_update

disable_imbus

disable_packet_sync

line_sync

prbs2

manager

pae_high_update

line_sync

prbs2

manager

mode_update

coeff_update

line_

sync

line_625_sync

Fig. 8–1: Task manager

Line

622

623

624

625

DMA2286 Datasheet(PDF) 12 Page - Micronas

DMA2286 Datasheet(HTML) 12 Page - Micronas

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

Datasheet Download

Link URL