Chapter 4 Memory
MC9S08QE128 MCU Series Reference Manual, Rev. 2
66
Freescale Semiconductor
4.4.2.5
Linear Byte Register (LB)
This register is one of three data registers that the user can use to access any flash memory location in the
extended address map. When LB is accessed the contents of LAP2:LAP0 make up the extended address
of the flash memory location to be addressed.
4.4.2.6
Linear Address Pointer Add Byte Register (LAPAB)
The user can increase or decrease the contents of LAP2:LAP0 by writing a 2s compliment value to
LAPAB. The value written will be added to the current contents of LAP2:LAP0.
4.4.3
Functional Description
4.4.3.1
Memory Expansion
The HCS08 Core architecture limits the CPU addressable space available to 64K bytes. The Program Page
(PPAGE) allows for integrating up to 4M byte of flash into the system by selecting one of the 16K byte
blocks to be accessed through the paging window located at 0x8000-0xBFFF. The MMU module also
provides a linear address pointer that allows extension of data access up to 4M bytes.
7
6
5
4
3
2
1
0
R
D7
D6
D5
D4
D3
D2
D1
D0
W
Reset:
0
0
0
0
0
0
0
0
Figure 4-8. Linear Byte Register (LB)
Table 4-9. Linear Data Register Field Descriptions
Field
Description
7:0
D7:D0
Reads of this register returns the data value pointed to by the linear address pointer, LAP2:LAP0. Writes to this
register will write the data value to the memory location specified by the linear address pointer. Writes to this
register are most commonly used when writing to the flash block(s) during programming.
7
6
5
4
3
2
1
0
R
0
0
0
0
0
0
0
0
W
D7
D6
D5
D4
D3
D2
D1
D0
Reset:
0
0
0
0
0
0
0
0
Figure 4-9. Linear Address Pointer Add Byte Register (LAPAB)
Table 4-10. Linear Address Pointer Add Byte Register Field Descriptions
Field
Description
7:0
D7:D0
The 2s compliment value written to LAPAB will be added to contents of the linear address pointer register,
LAP2:LAP0. Writing a value of 0x7f to LAPAB will increase LAP by 127, a value of 0xff will decrease LAP by 1,
and a value of 0x80 will decrease LAP by 128.
Содержание MC9S08QE128
Страница 2: ......
Страница 4: ......
Страница 49: ...Chapter 3 Modes of Operation MC9S08QE128 MCU Series Reference Manual Rev 2 50 Freescale Semiconductor ...
Страница 138: ...Chapter 6 Parallel Input Output Control MC9S08QE128 MCU Series Reference Manual Rev 2 138 Freescale Semiconductor ...
Страница 144: ...Chapter 7 Keyboard Interrupt S08KBIV2 MC9S08QE128 MCU Series Reference Manual Rev 2 144 Freescale Semiconductor ...
Страница 166: ...Chapter 8 Central Processor Unit S08CPUV4 MC9S08QE128 MCU Series Reference Manual Rev 2 166 Freescale Semiconductor ...
Страница 174: ...MC9S08QE128 MCU Series Reference Manual Rev 2 174 Freescale Semiconductor Analog Comparator S08ACMPV3 ...
Страница 202: ...12 bit Analog to Digital Converter S08ADCV1 MC9S08QE128 MCU Series Reference Manual Rev 2 202 Freescale Semiconductor ...
Страница 282: ...Serial Peripheral Interface S08SPIV3 MC9S08QE128 MCU Series Reference Manual Rev 2 282 Freescale Semiconductor ...
Страница 306: ...Timer PWM Module S08TPMV3 MC9S08QE128 MCU Series Reference Manual Rev 2 306 Freescale Semiconductor ...
Страница 320: ...Development Support MC9S08QE128 MCU Series Reference Manual Rev 2 320 Freescale Semiconductor ...