Memory Map for using external / internal Flash

Users Manual TOPAS900 Flash V2.1

	MEMORY MAP
	Boot Memory : internal ROM
	Reset-Conditions :
	/EA = H
	/BOOT = H
000000H		000000H
	Internal I/O

0000A0H	(160 bytes)	0000A0H
	Internal RAM

	(8K bytes)
0020A0H		0020A0H

external memory

MEMORY MAP

Boot Memory : external ROM Reset-Conditions :

/EA = L /BOOT = H

Internal I/O (160 bytes)

Internal RAM (8K bytes)

external memory

ROMSTART*

External Flash Memory (512 K bytes)

ext.	external memory
ROM

RAMSTART*

FC0000H

FFFF00H

FFFFFFH

External RAM (128 K bytes)

Internal Flash ROM (256K bytes)

Vector table (256 bytes)

RAMSTART*

F80000H

int.

ROM FFFF00H

FFFFFFH

External RAM (128 K bytes)

External Flash Memory (512 K bytes)

Vector table (256 bytes)

ext.

ROM

*ROMSTART is programmed by CS2 registers

*RAMSTART is programmed by CS1 registers

Figure 13 : Memory Map for using external / internal Flash

For programming the external flash the /EA line has to be set High which can be derived by opening the jumper J_EA (see fig. 1 at the right top and in the schematic fig. 10 at the bottom in the middle). The map of fig. 7 is valid and the external flash can be programmed supported by the 8-bit controller.

For normal operation and debugging it is important that the system starts from external flash, i.e. the vector table and the firmware have to be located and to be started from there. Like shown in the map of fig. 8 the external flash is located from off address F80000h to FFFFFFh including the vector area.

For running in normal operation the jumper J_EA can be left open, because the /EA line is controlled by the firmware controller. If the Flash Carrier Board works stand-alone (without Programming-and-Debugging Board), the jumper must be set when external

HWU Elektronik Oberhausen

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