S3F80JB

ADDRESS SPACES

 

 

REGISTER PAGE POINTER (PP)

The S3C8/S3F8-series architecture supports the logical expansion of the physical 333-byte internal register files (using an 8-bit data bus) into as many as 16 separately addressable register pages. Page addressing is controlled by the register page pointer PP (DFH, Set 1, Bank0). In the S3F80JB microcontroller, a paged register file expansion is not implemented and the register page pointer settings therefore always point to “page 0”.

Following a reset, the page pointer's source value (lower nibble) and destination value (upper nibble) are always '0000'automatically. Therefore, S3F80JB is always selected page 0 as the source and destination page for register addressing. These page pointer (PP) register settings, as shown in Figure 2-4, should not be modified during normal operation.

Register Page Pointer (PP)

DFH ,Set 1, Bank0, R/W

 

 

MSB

.7

.6

 

.5

.4

 

.3

 

 

.2

 

.1

 

.0

 

LSB

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Destination Register Page Seleciton Bits:

 

 

Source Register Page Selection Bits:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0 0 0

0

 

 

Destination: page 0

 

 

 

0

0 0 0

 

 

Source: page 0

NOTE:

 

 

 

 

 

A hardware reset operation writes the 4-bit destination and source values shown

 

 

above to the register page pointer. These values should not be modified to

 

 

address other pages.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 2-4. Register Page Pointer (PP)

2-7

Page 39
Image 39
Samsung S3F80JB manual Register page Pointer PP, Register Page Pointer PP