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Hi Roger, Here's how we do that sort of thing here (an example from one of our products, in the "linker.cmd" file). This example is for an '807 chip and external Data (X) memory, but the same thing will work for external P memory on the '803 and '805 chips. You do have to remember to use the SDK P memory access functions like memReadP16(), memWriteP16(), etc. when accessing any data in P memory, or to write your interface functions in assembler and use the P memory addressing modes when accessing this data. In the "MEMORY" section: .xExtUartA (RW) : ORIGIN = 0x4000, LENGTH = 0x0008 .xExtReservedA (RW) : ORIGIN = 0x4008, LENGTH = 0x0FF8 .xExtUartB (RW) : ORIGIN = 0x5000, LENGTH = 0x0008 .xExtReservedB (RW) : ORIGIN = 0x5008, LENGTH = 0x0FF8 .xExtFlash (RW) : ORIGIN = 0x6000, LENGTH = 0x1000 .xExtRTC (RW) : ORIGIN = 0x7000, LENGTH = 0x0010 .xExtReservedC (RW) : ORIGIN = 0x7010, LENGTH = 0x0FF0 .xExtRAM (RW) : ORIGIN = 0x8000, LENGTH = 0x7F80 .xExtRAM_Mirror (RWX) : ORIGIN = 0x8000, LENGTH = 0x7F80 In the "SECTIONS" section (at the end of the file): FExtUartA = ADDR(.xExtUartA); FExtUartB = ADDR(.xExtUartB); FExtFlash = ADDR(.xExtFlash); FExtRTC = ADDR(.xExtRTC); FExtRAM = ADDR(.xExtRAM); In one (or more) of the header (.h) files in your program: /* The location of the following structure is defined in linker.cmd */ extern XR16C2850_REGISTERS_T ExtUartA; /* The location of the following structure is defined in linker.cmd */ extern XR16C2850_REGISTERS_T ExtUartB; /* The location of the following array is defined in linker.cmd */ extern volatile WORD ExtFlash[]; /* The location of the following structure is defined in linker.cmd */ extern RTC7301SF_REGISTERS_T ExtRTC; /* The location of the following array is defined in linker.cmd */ extern volatile WORD ExtRAM[]; The above system is one of our custom designs that uses the '807 chip, so your memory map will be similar but NOT the same. What the above does is the following: 1) Assigns the XR16C2850_REGISTERS_T structure "ExtUartA" to be at address X:$4000 2) Assigns the XR16C2850_REGISTERS_T structure "ExtUartB" to be at address X:$5000 3) Assigns the volatile WORD array "ExtFlash" to be at address X:$6000 4) Assigns the RTC7301SF_REGISTERS_T structure "ExtRTC" to be at address X:$7000 5) Assigns the volatile WORD array "ExtRAM" to be at address X:$8000 Please note that in every case, the Linker Command File "linker.cmd" has the letter "F" added to the beginning of the variable name, this is a CodeWarrior convention. I am posting this message to the motoroladsp discussion group, as it contains information that should be useful to other members. I hope you find this information to be helpful. Regards, Art Johnson Senior Systems Analyst PMC Prime Mover Controls Inc. 3600 Gilmore Way Burnaby, B.C., Canada V5G 4R8 Phone: 604 433-4644 FAX: 604 433-5570 Email: http://www.pmc-controls.com -----Original Message----- From: Roger Flor [mailto:] Sent: Sunday, December 08, 2002 8:25 PM To: Art Johnson Subject: Writing to external Program memory Hello Art, I need some help. I am going to use a DSP56F803 but at the moment I am doing exploratory programming in a DSP56F805 EVM. I want to operate in Mode 0B and EX=0 mode. I want both program and data mamories to have external extensions. How do I write to external program memory using C (SDK)? I don't actually have an SRAM for external program memory (my SRAM is only for external data memory). I want to map an LCD controller to external program memory instead. That's why I need to write data to external program memory. I dont want to do address decoding, that's why I am not mapping the LCD controller to external data memory. I will be using the /PS signal as my LCD controller enable signal. Thanks in advance. Roger PS. If you feel that this might be useful in the yahoogroup, please feel free to post this in the group. Thanks. _________________________________________________________________ MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*. http://join.msn.com/?pageatures/virus |
RE: Writing to external Program memory
Started by ●December 9, 2002
