GMS81C2020 Datasheet, PDF (31/92 Pages) Hynix Semiconductor – CMOS Single-Chip 8-Bit Microcontroller with A/D Converter & VFD Driver

Hyundai Micro Electronics
GMS81C2020/GMS81C2120
11.3 Data Memory (GMS81C2020)
Figure 11-7 shows the internal Data Memory space avail-
able. Data Memory is divided into two groups, a user
RAM(including Stack) and control registers.
0000H
00BFH
00C0H
00FFH
0100H
01FFH
USER
MEMORY
CONTROL
REGISTERS
USER
MEMORY
( including STACK )
PAGE0
PAGE1
Figure 11-7 Data Memory Map
User Memory
The GMS81C2020 has 448 × 8 bits for the user memory
(RAM).
Control Registers
The control registers are used by the CPU and Peripheral
function blocks for controlling the desired operation of the
device. Therefore these registers contain control and status
bits for the interrupt system, the timer/ counters, analog to
digital converter, basic interval timer, serial peripheral in-
terface, watchdog timer, buzzer driver and I/O ports. The
control registers are in address range of 0C0_H to 0FF_H.
Note that unoccupied addresses may not be implemented
on the chip. Read accesses to these addresses will in gen-
eral return random data, and write accesses will have an in-
determinate effect.
More detailed informations of each register are explained
in each peripheral section.
Note: Write only registers can not be accessed by bit ma-
nipulation instruction. Do not use read-modify-write
instruction. Use byte manipulation instruction.
Example; To write at CKCTLR
LDM CKCTLR,#09H ;Divide ratio ÷16
Address Symbol R/W
RESET Addressing
Value
mode
0C0H
0C1H
0C2H
0C3H
0C4H
0C5H
0C6H
0C7H
0C8H
0C9H
0CAH
0CBH
0CCH
0CDH
0CEH
0CFH
R0
R0IO
R1
R1IO
R2
R2IO
R3
R3IO
R4
R4IO
R5
R5IO
R6
R6IO
R7
R7IO
R/W Undefined byte, bit¹
W 0000_0000 _byte²
R/W Undefined _{byte, bit}
W 00000000
byte
R/W Undefined _{byte, bit}
W 0000_0000 _byte
R/W Undefined _{byte, bit}
W --00_0000 _byte
R/W Undefined _{byte, bit}
W ----_0000 _byte
R/W Undefined _{byte, bit}
W 0000_0000 _byte
R/W Undefined _{byte, bit}
W 0000_0000 _byte
R/W Undefined _{byte, bit}
W ----_0000 _byte
0D0H
0D1H
0D1H
0D1H
0D2H
0D3H
0D3H
0D4H
0D4H
0D4H
0D5H
0DEH
TM0
T0
TDR0
CDR0
TM1
TDR1
T1PPR
T1
CDR1
T1PDR
PWM1HR
BUR
R/W
R
W
R
R/W
W
W
R
R
R/W
W
W
--00_0000
0000_0000
1111_1111
0000_0000
0000_0000
1111_1111
1111_1111
0000_0000
0000_0000
0000_0000
----_0000
1111_1111
byte, bit
byte
byte
byte
byte, bit
byte
byte
byte
byte
byte, bit
byte
byte
0E0H
0E1H
0E2H
0E3H
0E4H
0E5H
0E6H
0EAH
0EBH
0ECH
0ECH
0EDH
0EDH
0EFH
SIOM
SIOR
IENH
IENL
IRQH
IRQL
IEDS
ADCM
ADCR
BITR
CKCTLR
WDTR
WDTR
PFDR
R/W 0000_0001
R/W Undefined
R/W 0000_----
R/W 0000_----
R/W 0000_----
R/W 0000_----
R/W ----_0000
R/W -000_0001
R Undefined
R 0000_0000
W -001_0111
R 0000_0000
W 0111_1111
R/W ----_-100
byte, bit
byte, bit
byte, bit
byte, bit
byte, bit
byte, bit
byte, bit
byte, bit
byte
byte
byte
byte
byte
byte, bit
0F4H R0FUNC W ----_0000 byte
0F5H R4FUNC W ----_--00 byte
0F6H R5FUNC W 0000_0000 byte
0F7H R6FUNC W 0000_0000 byte
0F8H R7FUNC W ----_0000 byte
0F9H R5NODR W 0000_0000 byte
0FAH SCMR R/W ---0_0000 byte
0FBH
RA
R Undefined
-
Table 11-1 Control Registers
1. "byte, bit" means that register can be addressed by not only bit
but byte manipulation instruction.
2. "byte" means that register can be addressed by only byte
manipulation instruction. On the other hand, do not use any
read-modify-write instruction such as bit manipulation for
clearing bit.
Note: Several names are given at same address. Refer to
Nov. 1999 Ver 0.0
preliminary
31