Samsung S5PC100, Руководство пользователя

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S5PC100 USER’S MANUAL (REV1.0) JPEG
9.4-7
5 PROCESS
5.1 REGISTER ACCESS
The registers are modified
1. After reset, until a new job starts, or
2. After the generation of the process completion interruption signal, until a new job starts.
Other conditions indicate that the core is in the normal operation, therefore register modification is not
allowed.
5.2 TABLE ACCESS
Four Huffman tables (AC & DC, 2 tables for each) and four quantization tables must be configured before
compression. To set any quantization table and Huffman table, corresponding table entry register must be
accessed first. Then write transfers should follow. To understand the write transfer, refer to Figure 9.4-6. The
access order for each table is shown below.
3 4 1 2 7 8 5 6
11 12 9 10 15 16 13 14
19 20 17 18 23 24 21 22
27 28 25 26 31 32 29 30
35 36 33 34 39 40 37 38
43 44 41 42 47 48 45 46
51 52 49 50 55 56 53 54
59 60 57 58 63 64 61 62
Figure 9.4- 6 Access Order in Quantizer Table
5.3 STARTING PROCESS
Process start signal from the scheduler instructs to start compression or decompression process of one picture
after setting various registers. After getting the start signal, the core processing starts and then JPGOPR register
is read as 1. Operation cannot be guaranteed if the start signal is issued again during processing. Do not set like
that.