Samsung 8-Bit CMOS Microcontroller Microcassette Recorder User Manual


 
CONTROL REGISTERS S3C9228/P9228
4-4
FLAGS - System Flags Register
.7
.6
.5
Bit Identifier
RESET RESET Value
Read/Write
R = Read-only
W = Write-only
R/W = Read/write
' - ' = Not used
Bit number:
MSB = Bit 7
LSB = Bit 0
Addressing mode or
modes you can use to
modify register values
Description of the
effect of specific
bit settings
RESET value notation:
'-' = Not used
'x' = Undetermind value
'0' = Logic zero
'1' = Logic one
Bit number(s) that is/are appended to the
register name for bit addressing
D5H
Register address
(hexadecimal)
Full Register name
Register
mnemonic
Name of individual
bit or bit function
.7 .6 .5 .4 .2.3 .1 .0
x
R/W
x
R/W
x
R/W
x
R/W
0
R/W
x
R/W
0
R/W
x
R/W
Carry Flag (C)
0 Operation dose not generate a carry or borrow condition
1 Operation generates carry-out or borrow into high-order bit7
Zero Flag
0 Operation result is a non-zero value
1 Operation result is zero
Sign Flag
0 Operation generates positive number (MSB = "0")
1 Operation generates negative number (MSB = "1")
Figure 4-1. Register Description Format