Ingenic Jz47xx Series
Ingenic seems to have released a lot of information regarding their chipsets including (GPL'ed) source code. Although, not everything is publicly on their FTP server; what's missing exactly are the datasheets, MXU instruction datasheet, ...
All the boards in the Jz47xx series consist of a XBurst processor, which is a MIPS processor clocked at 240->400Mhz.
Jz4720 is a low cost multimedia application processor targeting for mobile devices like MP4 players, electronic dictionaries, ...
Jz4730 is a multimedia application processor incorporating XBurst technology targeted at mobile and general embedded devices.
The CPU core is based on leading micro-architecture technology; this processor provides high integration, high performance and a low power consumption solution for embedded devices.
This chipset is undocumented, but believed to be a modified Jz4740.
Ingenic seems to say that it is a Jz4740 meant for exportation outside China.
The processor itself is identified as 0x0AD0024F (which is the same as the Jz4740).
Refer to the Jz4740 for more information.
The Jz4732/Jz4740 is a popular choice among some Chinese MP4 players.
Jz4740 is a multimedia application processor targeted at mobile devices like smart-phone, PMP and GPS.
Incorporates the XBurst CPU core based on leading micro-architecture technology, this processor provides high integration, high performance and a low power consumption solution for embedded devices.
C0_CONFIG1 has this value: 0x3E63318A
- EJTAG present
- watch registers present
- Dcache associativity = 3
- Dcache line size = 4
- Dcache sets per way = 1
- Icache associativity = 4
- Icache line size = 4
- Icache sets per way = 1
- Number of MMU entries = 32
- VA: 0x080000000 -> 0x080004000 = 16KB I-Cache
- VA: 0x080000080 = IRQ handler/ISR
- VA: 0x080000200 = IRQ handler/ISR when IV is set in C0_CAUSE
- VA: 0xBXXXXXXX | PA: 0x1XXXXXXX = hardware memory registers
- VA: 0xBFC00000 -> 0xBFC01000 | PA: 0x1FC00000 -> 0x1FC01000 = On-chip Boot ROM
The Jz4740 can be set to boot from NOR or NAND.
If booted from NAND, the CPU fetches the first page from NAND and uses the first 4 bytes on it to know how the NAND chip should be treated (16/8-bit bus, 2/3 row cycles).
After that it copies the first 8kB from NAND and copies it to the I-Cache for execution.
Ingenic Media Extension Instruction Set
According to the MXU User Guide, the XBurst processor supports additional instructions called the Ingenic Media Extension Instruction Set (they call it an SIMD instruction set).
Excerpt from the PDF:
Processors (such as the Jz4740) have 60 extra SIMD commands used for the optimization of multimedia codecs such as MPEG4, H264, VC-1, RMVB, ... and other multimedia decoder algorithms that can be optimized using the MXU.
Image Processing Unit
The Jz4740 also has an IPU which has the following features:
- Video frame resize
- Color space conversion: 420/444/422 YUV to RGB convert
Ingenic provides a lot of (GPL) source code for their boards.
As their FTP server is rather slow, I mirrored some files:
Copyright © by the contributing authors.