CHAPTER 2: INITIAL RESET
II-9
INITIAL RESET
Internal Register Status on Initial Reset
Following an initial reset, the internal registers and internal
data memory area are initialized to the values shown in
Tables 2.1.1 and 2.1.2.
Internal Register
Bit Length
Initial Value Following Reset
Program counter step
PCS
8
00H
Program counter page
PCP
4
1H
New page pointer
NPP
4
1H
Stack pointer
SP
8
Undefined
Index register
X
8
Undefined
Index register
Y
8
Undefined
Register pointer
RP
4
Undefined
General register
A
4
Undefined
General register
B
4
Undefined
Interrupt flag
I
1
0
Decimal flag
D
1
0
Zero flag
Z
1
Undefined
Carry flag
C
1
Undefined
Internal Data
Initial Value
Memory Area
Following Reset
RAM data
4
×
80
Undefined
000H–05FH
Display memory
4
×
20
Undefined
090H–0AFH
Internal I/O register
See Tables 1.4.1(a)–1.4.1(d)
0E0H–0FDH
2.1
Table 2.1.1
Initial values of internal
registers
CHAPTER 2
Table 2.1.2
Initial values of internal data
memory area
Bit Length
Address