Samsung KS57C2308 Manual page 33

KS57C2308/P2308/C2316/P2316
EMB AND ERB INITIALIZATION VALUES
The EMB and ERB flag bits are set automatically by the values of the
vector address. When a
EMB flag, initializing it automatically. When a vectored interrupt is generated, bit 7 of the respective vector
address table is written to the EMB. This automatically sets the EMB flag status for the interrupt service routine.
When the interrupt is serviced, the EMB value is automatically saved to stack and then restored when the
interrupt routine has completed.
At the beginning of a program, the initial EMB and ERB flag values for each vectored interrupt must be set by
using VENT instruction. The EMB and ERB can be set or reset by bit manipulation instructions (BITS, BITR)
despite the current SMB setting.
+ +
PROGRAMMING TIP — Initializing the EMB and ERB Flags
The following assembly instructions show how to initialize the EMB and ERB flag settings:
ORG
VENT0
VENT1
VENT2
VENT3
VENT4
VENT5
•
•
•
RESET BITR
is generated internally, bit 7 of program memory address 0000H is written to the
RESET
0000H ; ROM address assignment
1,0,RESET ; EMB
0,1,INTB ; EMB
0,1,INT0 ; EMB
0,1,INT1
; EMB
0,1,INTS
; EMB
0,1,INTT0 ; EMB
EMB
1, ERB 0, branch RESET
0, ERB 1, branch INTB
0, ERB 1, branch INT0
0, ERB 1, branch INT1
0, ERB 1, branch INTS
0, ERB 1, branch INTT0
ADDRESSING MODES
vector address and the interrupt
RESET
3-3