MC68HC12 Datasheet, PDF (93/478 Pages) Motorola, Inc – The MC68HC912DT128A microcontroller unit (MCU) is a 16-bit device composed of standard on-chip peripherals including a 16-bit central processing unit

Resource Mapping
Flash EEPROM mapping through internal Memory Expansion
Table 6-2. Program space Page Index
Page Index 2 Page Index 1 Page Index 0
(PPAGE bit 2) (PPAGE bit 1) (PPAGE bit 0)
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
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
16K byte Page 6*
16K byte Page 7*
Flash array
00FEE32K
00FEE32K
01FEE32K
01FEE32K
10FEE32K
10FEE32K
11FEE32K
11FEE32K
* The 16K byte flash in program space page 6 can also be accessed at
a fixed location from $4000 to $7FFF. The 16K byte flash in program
space page 7 can also be accessed at a fixed location from $C000 to
$FFFF.
6.4.2 Flash register space expansion
There are four 32K Flash arrays for MC68HC912DT128A and each
requires a 4-byte register block. A register space window is used to
access one of the four 4-byte blocks and the PPAGE register to map
each one into the window. The register space window is located from
$00F4 to $00F7 after reset. Only two page indices are used to point to
one of the four pages of the register space.
Table 6-3. Flash Register space Page Index
Page Index 2
(PPAGE bit
2)
0
0
1
1
Page Index 1
(PPAGE bit 1)
0
1
0
1
Page Index 0
(PPAGE bit 0)
X
X
X
X
Flash register space Page
$00F4-$00F7 Page 0
$00F4-$00F7 Page 1
$00F4-$00F7 Page 2
$00F4-$00F7 Page 3
Flash array
00FEE32K
01FEE32K
10FEE32K
11FEE32K
MC68HC912DT128A — Rev 4.0
MOTOROLA
Resource Mapping
Technical Data
93