Flags System Flags Register - Samsung S3C80M4/F80M4 User Manual

S3C80M4/F80M4
Bit number(s) that is/are appended to
the register name for bit addressing
Register ID
FLAGS - System Flags Register
Bit Identifier
RESET Value
Read/Write
Bit Addressing
Mode
.7
.6
.5
R = Read-only
W = Write-only
R/W = Read/write
'-' = Not used
Type of addressing
that must be used to
address the bit
(1-bit, 4-bit, or 8-bit)
Name of individual
bit or related bits
Full Register name
.7 .6 .5
x x x
R/W R/W R/W
Register addressing mode only
Carry Flag (C)
0 Operation does not generate a carry or borrow condition
0 Operation generates carry-out or borrow into high-order bit 7
Zero Flag (Z)
Operation result is a non-zero value
0
Operation result is zero
0
Sign Flag (S)
Operation generates positive number (MSB = "0")
0
Operation generates negative number (MSB = "1")
0
Description of the
effect of specific
bit settings
Figure 4-1. Register Description Format
Register address
(hexadecimal)
D5H
.4 .3 .2
x x x
R/W R/W R/W
CONTROL REGISTER
Register location
in the internal
register file
Set 1
.1 .0
x 0
R/W R/W
Bit number:
MSB = Bit 7
LSB = Bit 0
RESET value notation:
'-' = Not used
'x' = Undetermined value
'0' = Logic zero
'1' = Logic one
4-3