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Hi! I'm using XBANKING.a51 from "Keil\C51\Examples\FarMemory\3 XData Areas on T89C51RD2" for access to various types of memory MCU Atmel AT89C5131. I'm define memory model - Large, "User Classes" as: XDATA (X:0x008000-X:0x009FFE) // off-chip XRAM HDATA_EEPROM (X:0x020000-X:0x0207FF) // on-chip EEPROM HDATA (X:0x010000-X:0x0103FF) // on-chip XRAM And variables as: in file MAIN.c unsigned char *Pointer1, *Pointer2; unsigned char far onBufer; // on-chip XRAM unsigned char xdata offBufer; // off-chip XRAM unsigned code cBufer = "Welcome"; // on-chip ROM in file EEPROM.c #pragma USERCLASS (HDATA = EEPROM) unsigned char far EEBufer; // on-chip EEPROM I'm programming next code: Pointer1 = onBufer; // pointer to 0x01AABB Pointer2 = cBuffer; // pointer to 0xFFCCDD memcpy(Pointer1, Pointer2, 20); Compiling my program and view "Disassembly Window": ... Pointer1 = onBuffer; 908010 MOV DPTR,#Pointer1(0x8010) 7402 MOV A,#0x02 // on-chip EEPROM area !!! F0 MOVX @DPTR,A A3 INC DPTR 74AA MOV A,#0xAA F0 MOVX @DPTR,A A3 INC DPTR 74BB MOV A,#0xBB F0 MOVX @DPTR,A Pointer2 = cBuffer; A3 INC DPTR 74FF MOV A,#0xFF F0 MOVX @DPTR,A A3 INC DPTR 74CC MOV A,#0xCC F0 MOVX @DPTR,A A3 INC DPTR 74DD MOV A,#0xDD F0 MOVX @DPTR,A memcpy(Pointer1, Pointer2, 20); ... Where the bug or my error?
Did you notice that the EEPROM variables are defined in a USER_CLASS.
#pragma ORDER // keep variables in order of definition #pragma USERCLASS (HDATA = EEPROM) // use HDATA_EEPROM for E2PROM area #define DECLARE #include <eeprom.h> // include all variables
OK, I have understood, it turns out, that memory and indexes are allocated as follows:
+----------------+--------------+------------------------+--------------+-----------+ | Memory Type | Memory Class | Define in C language | Address in C | R3 in ASM | +----------------+--------------+------------------------+--------------+-----------+ | on-chip XDATA | HDATA | far | X:0x010000 | 0x02 | | off-chip XDATA | XDATA | xdata | X:0x000000 | 0x01 | | CODE | CODE | code | X:0x0000 | 0xFF | | EEPROM | HDATA_EEPROM | far & (HDATA = EEPROM) | C:0x0000 | 0x03 | +----------------+--------------+------------------------+--------------+-----------+ * using standard files XBANKING.a51 and EEPROM.c
There is another problem. In the menu "Options for Target" I choose "Memory Model = Lage: variables in XDATA". I have function in my program char Test (char value1, char *value2, char value3) in which parameters transferred through XDATA memory, but not through registers. XDATA memory is an off-chip. How to transfer parameters through on-chip XRAM?
There is no particular reason why on-chip XDATA has to be HDATA, while off-chip is XDATA.
Presumably, you are looking at some specific case where this happened to be (or seem) convenient to whoever set it up?
I shall ask on another. I define variables as:
char xdata A; // locate in off-chip XDATA char far B; // locate in on-chip XDATA
If the model of memory LARGE and a variable is defined as char C; , then where is placed a variable? It is necessary for me that in on-chip XDATA.
"It is necessary for me that in on-chip XDATA."
If it is necessary, then just specify it explicitly. Simple.