RESET
and POWER-DOWN
S3C80A5B
8-4
HARDWARE RESET VALUES
Tables 5-1 list the reset values for CPU and system registers, peripheral control registers, and peripheral data
registers following a reset operation. The following notation is used to represent reset values:
— A "1" or a "0" shows the reset bit value as logic one or logic zero, respectively.
— An 'x' means that the bit value is undefined after a reset.
— A dash ('-') means that the bit is either not used or not mapped (but a 0 is read from the bit position)
Table 8-1. Set 1 Register Values After Reset
Register Name
Mnemonic
Address
Bit Values After Reset
Dec
Hex
7
6
5
4
3
2
1
0
Timer 0 counter (read-only)
T0CNT
208
D0H
0
0
0
0
0
0
0
0
Timer 0 data register
T0DATA
209
D1H
1
1
1
1
1
1
1
1
Timer 0 control register
T0CON
210
D2H
0
0
0
0
0
0
0
0
Basic timer control register
BTCON
211
D3H
0
0
0
0
0
0
0
0
Clock control register
CLKCON
212
D4H
0
0
0
0
0
0
0
0
System flags register
FLAGS
213
D5H
×
×
×
×
×
×
0
0
Register pointer 0
RP0
214
D6H
1
1
0
0
0
–
–
–
Register pointer 1
RP1
215
D7H
1
1
0
0
1
–
–
–
Location D8H (SPH) is not mapped.
Stack pointer (low byte)
SPL
217
D9H
×
×
×
×
×
×
×
×
Instruction pointer (high byte)
IPH
218
DAH
×
×
×
×
×
×
×
×
Instruction pointer (low byte)
IPL
219
DBH
×
×
×
×
×
×
×
×
Interrupt request register (read-only)
IRQ
220
DCH
0
0
0
0
0
0
0
0
Interrupt mask register
IMR
221
DDH
×
×
×
×
×
×
×
×
System mode register
SYM
222
DEH
0
–
–
×
×
×
0
0
Register page pointer
PP
223
DFH
0
0
0
0
0
0
0
0
Port 0 data register
P0
224
E0H
0
0
0
0
0
0
0
0
Port 1 data register
P1
225
E1H
0
0
0
0
0
0
0
0
Port 2 data register
P2
226
E2H
0
0
0
0
0
0
0
0
Location E3H–E6H is not mapped.
Port 0 pull-up enable register
P0PUR
231
E7H
0
0
0
0
0
0
0
0
Port 0 control register (high byte)
P0CONH
232
E8H
0
0
0
0
0
0
0
0
Port 0 control register (low byte)
P0CONL
233
E9H
0
0
0
0
0
0
0
0