From ef83ff14c2240b2353a4532990f663db8a4626ad Mon Sep 17 00:00:00 2001 From: xiangfu Date: Tue, 16 Jun 2009 07:29:07 +0000 Subject: [PATCH] add more info of jz4740 to README --- README | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/README b/README index e1d607a..5d7af93 100644 --- a/README +++ b/README @@ -18,3 +18,20 @@ PMP. 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. +Boot up +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 +