PSD913F1-B-90JI ST Microelectronics, PSD913F1-B-90JI Datasheet - Page 34

• Manufacturer Part Number: PSD913F1-B-90JI
• Description: Flash In-System Programmable ISP Peripherals For 8-bit MCUs
• Manufacturer: ST Microelectronics

The
PSD9XX
Functional
Blocks
(cont.)
30
PSD9XX Family
9.1.4 Page Register
The eight bit Page Register increases the addressing capability of the microcontroller by a
factor of up to 256. The contents of the register can also be read by the microcontroller.
The outputs of the Page Register (PGR0-PGR7) are inputs to the PLD and can be
included in the Flash Memory, Secondary Flash Block, and SRAM chip select equations.
If memory paging is not needed, or if not all 8 page register bits are needed for memory
paging, then these bits may be used in the PLD for general logic. See Application
Note.
Figure 8 shows the Page Register. The eight flip flops in the register are connected to the
internal data bus D0-D7. The microcontroller can write to or read from the Page Register.
The Page Register can be accessed at address location CSIOP + E0h.
Figure 8. Page Register
RESET
D 0 - D7
R/W
D0
D1
D2
D3
D4
D5
D6
D7
REGISTER
PAGE
Q 0
Q 1
Q 2
Q 3
Q 4
Q 5
Q 6
Q 7
PGR0
PGR1
PGR2
PGR3
PGR4
PGR5
PGR6
PGR7
FLASH
DPLD
GPLD
PLDs
AND
Preliminary Information
INTERNAL
SELECTS
AND LOGIC