MV20556 Datasheet, PDF (7/30 Pages) Mosel Vitelic, Corp – 8 - Bit MCU Mouse Controller

MOSEL VITELIC INC.
Preliminary
MV20556
Memory Map Details (Cont'd)
Special Function Registers (SFR)
The Special Function Registers include arithmetic
registers (Acc, B, PSW), pointers (SP, DPH, DPL) and
registers that provide an interface between the CPU
and the on-chip peripheral functions. These are also
128 addressable bits within the Special Function
Registers. The memory-mapped locations of these
registers and bits are shown in right side figure.
Acc Register
The Acc register is the accumulator.
Program Status Word Register
The carry (CY), auxiliary carry (AC), user flag 0 (F0),
register bank select (RS0 and RS1), overflow (OV) and
parity (P) flags reside in the Program Status Word
(PSW) Register. These flags are bit-memory-mapped
within the byte-memory-mapped PSW. The PSW flags
record processor status information and control the
operation of the processor.
The CY, AC, and OV flags generally reflect the status
of the latest arithmetic operations. The P flag always
reflects the parity of the Acc register. The carry flag is
also the Boolean accumulator for bit operations.
B Register
The B register is dedicated during multiply and divide
and serves as both a source and a destination. During
all other operations the B register is simply another
location of the Special Function Register space.
Direct
Byte
Address ^(MSB)
Bit Addresses
Hardware
Register
(LSB) _Symbol
240 F7 F6 F5 F4 F3 F2 F1 F0 B
224 E7 E6 E5 E4 E3 E2 E1 E0 Acc
CY AC FO RS1 RS0 OV
P
208 D7 D6 D5 D4 D3 D2 D1 D0 PSW
184 -
-
PS PT1 PX1 PT0 PX0
-
BC BB BA B9 B8 IP
176 B7 B6
EA
168 AF
-
B5 B4 B3 B2 B1 B0 P3
ES ET1 EX1 ET0 EX0
-
AC AB AA A9 A8 IE
160 A7 A6 A5 A4 A3 A2 A1
SM0 SM1 SM2 REN TB8 RB8 TI
152 9F 9E 9D 9C 9B 9A 99
A0 P2
RI
98 SCON
144 97
96
95
94
93
92
91
90 P1
TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0
136 8F 8E 8D 8C 8B 8A 89 88 TCON
128 87
86
85
84
83
82
81
80 P0
SYMBOLIC
ADDRESS
BIT ADDRESS
BYTE
ADDRESS
255
B
247
Acc
231
PSW
215
IPC
191
P3
183
IEC
175
P2
167
SBUF
SCON
159
P1
151
TH1
TH0
TL1
TL0
TMOD
TCON
143
DPH
DPL
SP
P0
135
248
240 (F0H)
240
224 (E0H)
224
208 (D0H)
208
184 (B8H)
184
176 (B0H)
176
168 (A8H)
168
160 (A0H)
160
153 (99H)
152 (98H)
152
144 (90H)
144
141 (8DH)
140 (8CH)
139 (8BH)
138 (8AH)
137 (89H)
136 (88H)
136
131 (83H)
130 (82H)
129 (81H)
128 (80H)
128
SFR's
Containing
Direct
Addressable
Bits
SFR Bit Address
Specifications subject to change without notice, contact your sales representatives for the most recent information.
7/27
SFR Memory Map
PID256** 07/97