MC912DG128A Motorola, MC912DG128A Datasheet - Page 73

• Manufacturer Part Number: MC912DG128A
• Description: Microcontrollers
• Manufacturer: Motorola

Program space
expansion
5-mapping
MOTOROLA
(PPAGE bit 2)
Page Index 2
0
0
0
0
1
1
(PPAGE bit 1)
Page Index 1
0
0
1
1
0
0
space window, a register space window for Flash module registers, and
a test program space window.
The user’s program page window consists of 16K Flash EEPROM bytes.
One of eight pages is viewed through this window for a total of 128K
accessible Flash EEPROM bytes.
The register space window consists of a 4-byte register block. One of
four pages is viewed through this window for each of the 32K flash
module register blocks of MC68HC912DT128A.
The test mode program page window consists of 32K Flash EEPROM
bytes. One of the four 32K byte arrays is viewed through this window for
a total 128K accessible Flash EEPROM bytes. This window is only
available in special mode for test purposes and replaces the user’s
program page window.
MC68HC912DT128A has a five pin port, port K, for emulation and for
general purpose I/O. Three pins are used to emulate the three page
indices (PPAGE bits) and one pin is used as an emulation chip select.
When these four pins are not used for emulation they serve as general
purpose I/O pins. The fifth port K pin is used as a general purpose I/O
pin.
There are 128K bytes of Flash EEPROM for MC68HC912DT128A. With
a 64K byte address space, the PPAGE register is needed to perform on
chip memory expansion. A program space window of 16K byte pages is
located from $8000 to $BFFF. Three page indices are used to point to
one of eight different 16K byte pages.
Table 11 Program space Page Index
(PPAGE bit 0)
Page Index 0
0
1
0
1
0
1
Resource Mapping
Flash EEPROM mapping through internal Memory Expansion
16K Program space Page
16K byte Page 0
16K byte Page 1
16K byte Page 2
16K byte Page 3
16K byte Page 4
16K byte Page 5
MC68HC912DT128A Rev 2.0
Flash array
00FEE32K
00FEE32K
01FEE32K
01FEE32K
10FEE32K
10FEE32K
Resource Mapping
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