KeilC51v612

Working with Dallas 390 CPU in Contigious Addressing Mode ********************************************************* ----------------------------------------------------------------------------- NOTE: For supporting of the Dallas 390 or Dallas 5240 CPU in Contigious Mode, the Keil PK51 V6.11 offers the extended LX51 linker/locater and the extended AX51 Macro Assembler. The instruction set itself is supported directly in the Keil C51 Compiler with additional C51 run-time library sets. These components are only part of the Keil PK51 package and not available in the CA51 or DK51 toolkit. ----------------------------------------------------------------------------- The following README file explains how to setup and how to use the Keil PK51 toolchain for the Contigious Addressing Mode of the Dallas 390 CPU and Dallas 5240 CPU. Tool Setup ========== The following steps are required to setup the toolchain for Dallas Contigious Mode: a) Create a new Project with Project - New Project and select from the uVision2 Device Database the Dallas DS80C390 (or DS5240) CPU. In the dialog Project - Select Device for Target - CPU enable both options: Use LX51 instead of BL51 Use AX51 instead of A51 b) Now you can select in the dialog Project - Options for Target - Target - Code ROM Size: Contigious Mode: 512K program or 16MB program. This option configures all tools including debugger/simulator for the Dallas contigious mode. However, you need a proper startup sequence in your application code that sets the SFR ACON in the Dallas CPU also to this operating mode. Additional Memory Spaces ======================== In addition to the memory classes of the classic 8051 CPU, the extended 8051 toolchain adds three additional memory classes. These memory classes are described in detail the Assembler/Utilities User's Guide (A51.PDF), Chapter 2 Architecture Overview, Extended 8051 Variants. Class C51 memory type Allows Addressing of... --------------------------------------------------------------------------------- HCONST const far complete CODE space C:0 - C:0xFFFFFF for constant variables. HDATA far complete XDATA space X:0 - C:0xFFFFFF for variables ECODE C program code complete CODE space for program code. Porting Existing 8051 Assembler Code to the Dallas Contigious Mode ================================================================== As explained above the new toolchain supports additional memory classes for addressing the extended memory areas of the Dallas 390 CPU. However, if you are porting existing 8051 assembler code to the Dallas Contigious Mode, the existing code is still used 16-bit address calculations. If you do not want to work over the existing 8051 assembler code, you can still use the old traditional memory classes CODE and XDATA. These memory classes ensure that the objects are located in the lower 64KB of the CODE and XDATA region. In this way existing 16-bit address calculation will still work correct. Porting Existing C Code to the Dallas Contigious Mode ===================================================== You can find a startup code for the Dallas Contigious Mode in the folder Keil\C51\Examples\Dallas 390\C. It is recommended that you are using the START390.A51 file also for own projects. Function Pointers ================= Since the Dallas 390 supports up to 16MB program space, it is no longer possible to use code * as function pointers. You need to use a generic pointer when you define a function pointer. Accessing 16MB memory on the Dallas 390 ======================================= C51 Version 6.11 provides two new memory types that can be used to access the extended XDATA and the extended CODE space. The memory types are: far and const far. The following example shows you how to use these memory types: char far farray[0x300]; // this is a variable in HDATA space const char far ctext[] = "This is a string in ECODE space"; Downloading Programs to the Systronix uCAN2 Evaluation Board ============================================================ You can download the programs written with the Keil C51 Compiler to the Systronix uCAN2 Evaluation Board. The following steps are required: a) Connect the COM1(Loader) port on the Systronix uCAN2 Evaluation Board to the PC as described in the Systronix user's guide. b) Switch the board to the Loading Mode by pressing LOAD button. c) Open a terminal emulation (like Hyperterminal) and start a connection with 19200baud (8bits, no parity, 1 stop-bit, xon/xoff). d) Press Enter to start the loader and send the command L <Enter> to the board. e) Now you can send the generated HEX-File to the board. In Hyperterminal you can use the menu command 'Send - Text File' to perform this action. f) After loading you can execute the program by pressing 'Reset'. ------------------------------------------------------------------------------ NOTE: Currently is no Keil ROM Monitor available for the Dallas 390 contigious mode. ------------------------------------------------------------------------------