Samsung KS57C2308 Manual page 23

KS57C2308/P2308/C2316/P2316
BIT SEQUENTIAL CARRIER (BSC)
The bit sequential carrier (BSC) is a 16-bit general register that can be manipulated using 1-, 4-, and 8-bit RAM
control instructions.
RESET
Using the BSC, you can specify sequential addresses and bit locations using 1-bit indirect addressing
(memb.@L). (Bit addressing is independent of the current EMB value.) In this way, programs can process 16-bit
data by moving the bit location sequentially and then incrementing or decreasing the value of the L register.
BSC data can also be manipulated using direct addressing. For 8-bit manipulations, the 4-bit register names
BSC0 and BSC2 must be specified and the upper and lower 8 bits manipulated separately.
If the values of the L register are 0H at BSC0.@L, the address and bit location assignment is FC0H.0. If the L
register content is FH at BSC0.@L, the address and bit location assignment is FC3H.3.
Name
BSC0
BSC1
BSC2
BSC3
+ +
PROGRAMMING TIP — Using the BSC Register to Output 16-Bit Data
To use the bit sequential carrier (BSC) register to output 16-bit data (5937H) to the P3.0 pin:
BITS
SMB
LD
LD
LD
LD
SMB
LD
AGN LDB
LDB
INCS
JR
RET
clears all BSC bit values to logic zero.
Table 2-4. BSC Register Organization
Address Bit 3
FC0H BSC0.3
FC1H BSC1.3
FC2H BSC2.3
FC3H BSC3.3
EMB
15
EA,#37H
BSC0,EA
EA,#59H
BSC2,EA
0
L,#0H
C,BSC0.@L
P3.0,C
L
AGN
Bit 2
BSC0.2
BSC1.2
BSC2.2
BSC3.2
;
; BSC0 A, BSC1
;
; BSC2 A, BSC3
;
;
; P3.0 C
ADDRESS SPACES
Bit 1 Bit 0
BSC0.1 BSC0.0
BSC1.1 BSC1.0
BSC2.1 BSC2.0
BSC3.1 BSC3.0
E
E
2-15