NT6862-5xxxx
9
3. RAM: 512 X
8 bits
The built-in 512 X 8-bit SRAM is used for data memory and stack area. The RAM addressing range is from $0080 to $027F.
The contents of RAM are undetermined at power-up and are not affected by system reset. Software programmers can
allocate stack area in the RAM by setting stack pointer register (S). Because the 6502 default stack pointer is $01FF,
programmers must set S register to FFH when starting the program.
as;
LDX
#$FF
TXS
RAM
Unused
ROM
$0000
$0080
$8000
$FFFF
stack pointer
$FFFE
$FFFD
$FFFC
RST-L
RST-H
IRQ-L
IRQ-H
RESET vector
IRQ vector
$027F
$0280
( 32 K Bytes )
$003D
System Registers
Unused
$7FFF
( 512 Bytes )
$FFFB
$FFFA
NMI-L
NMI-H
NMI vector
$01FF
4. ROM: 32K X
8
bits
NT6862 provides maximum 32K ROM space for code. The ROM space is located from $8000 to $FFFF.
The addresses, from $FFFA to $FFFF, are reserved for the 6502 CPU vectors, thus users must arrange them sepately.