KS57C2308/P2308/C2316/P2316

ADDRESS SPACES

 

 

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 clears all BSC bit values to logic zero.

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.

Table 2-4. BSC Register Organization

Name

Address

Bit 3

Bit 2

Bit 1

Bit 0

 

 

 

 

 

 

BSC0

FC0H

BSC0.3

BSC0.2

BSC0.1

BSC0.0

 

 

 

 

 

 

BSC1

FC1H

BSC1.3

BSC1.2

BSC1.1

BSC1.0

 

 

 

 

 

 

BSC2

FC2H

BSC2.3

BSC2.2

BSC2.1

BSC2.0

 

 

 

 

 

 

BSC3

FC3H

BSC3.3

BSC3.2

BSC3.1

BSC3.0

 

 

 

 

 

 

+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

EMB

 

 

 

SMB

15

 

 

 

LD

EA,#37H

;

 

 

LD

BSC0,EA

;

BSC0 A, BSC1 E

 

LD

EA,#59H

;

 

 

LD

BSC2,EA

;

BSC2 A, BSC3 E

 

SMB

0

 

 

 

LD

L,#0H

;

 

AGN

LDB

C,BSC0.@L

;

 

 

LDB

P3.0,C

;

P3.0 C

 

INCS

L

 

 

 

JR

AGN

 

 

 

RET

 

 

 

2-15

Page 23
Image 23
Samsung KS57C2308 manual BSC Register Organization Name Address Bit