Changes between Version 1 and Version 2 of ppc_prog_overview/EDK_prog
- Timestamp:
- Aug 3, 2006, 12:04:13 AM (18 years ago)
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ppc_prog_overview/EDK_prog
v1 v2 45 45 If the user is developing a custom peripheral [http://warp.rice.edu/trac/wiki/custom_periphs/yes_PPC to be controlled by the PPC], chances are that it has been created in one of two ways: by using the “create/import peripheral” wizard, or through System Generator. The former will generate a basic API and the latter will simply generate a header file of base addresses. In either case, if the developer knows the proper coding of bits for a control register or wants to read/write data from a register, creating an expanded API is a simple matter of using pointers. [[BR]][[BR]] 46 46 Alternatively, Xilinx provides a library called “'''xio.h''',” which gives the user a host of abstract lower-level functions. The most useful of these are XIo_In16( ) and XIo_Out16( ), which are also available in the 8bit-wide and 32bit-wide varieties. The XIo_In functions allow a user to read data from a register by providing a base-address and an offset. The XIo_Out functions allow a user to write data to a register by providing a base address, an offset, and the data value. The library header can be found in: '''$EDK\sw\XilinxProcessorIPLib\drivers\cpu_ppc405_v1_00_a\src\xio.h''' 47 48 49 50 51 47 [[BR]] 52 48 [wiki:ppc_prog_overview/edkgcc PREV: GCC in EDK] ||| [wiki:ppc_prog_overview HOME] ||| [wiki:ppc_prog_overview/xilkernel NEXT: Xilkernel Support and Programming]