MC9S08QG8_09 Datasheet, PDF (43/314 Pages) Freescale Semiconductor, Inc – HCS08 Microcontrollers

Chapter 4 Memory Map and Register Definition
4.3 Register Addresses and Bit Assignments
The registers in the MC9S08QG8/4 are divided into these groups:
• Direct-page registers are located in the first 96 locations in the memory map; these are accessible
with efficient direct addressing mode instructions.
• High-page registers are used much less often, so they are located from 0x1800 and above in the
memory map. This leaves more room in the direct page for more frequently used registers and
RAM.
• The nonvolatile register area consists of a block of 16 locations in FLASH memory at
0xFFB0–0xFFBF. Nonvolatile register locations include:
— NVPROT and NVOPT are loaded into working registers at reset.
— An 8-byte backdoor comparison key that optionally allows a user to gain controlled access to
secure memory.
Because the nonvolatile register locations are FLASH memory, they must be erased and
programmed like other FLASH memory locations.
Direct-page registers can be accessed with efficient direct addressing mode instructions. Bit manipulation
instructions can be used to access any bit in any direct-page register. Table 4-2 is a summary of all
user-accessible direct-page registers and control bits.
The direct page registers in Table 4-2 can use the more efficient direct addressing mode that requires only
the lower byte of the address. Because of this, the lower byte of the address in column one is shown in bold
text. In Table 4-3 and Table 4-4, the whole address in column one is shown in bold. In Table 4-2, Table 4-3,
and Table 4-4, the register names in column two are shown in bold to set them apart from the bit names to
the right. Cells that are not associated with named bits are shaded. A shaded cell with a 0 indicates this
unused bit always reads as a 0. Shaded cells with dashes indicate unused or reserved bit locations that could
read as 1s or 0s.
Table 4-2. Direct-Page Register Summary
Address Register Name
0x0000
0x0001
PTAD
PTADD
0x0002 PTBD
0x0003
0x0004–
0x000B
0x000C
PTBDD
Reserved
KBISC
0x000D KBIPE
0x000E
0x000F
KBIES
IRQSC
0x0010 ADCSC1
0x0011
0x0012
ADCSC2
ADCRH
0x0013 ADCRL
Bit 7
0
0
PTBD7
PTBDD7
—
—
0
KBIPE7
KBEDG7
0
COCO
ADACT
0
ADR7
6
0
0
PTBD6
PTBDD6
—
—
0
KBIPE6
KBEDG6
IRQPDD
AIEN
ADTRG
0
ADR6
5
PTAD5
PTADD5
PTBD5
PTBDD5
—
—
0
KBIPE5
KBEDG5
0
ADCO
ACFE
0
ADR5
4
PTAD4
PTADD4
PTBD4
PTBDD4
—
—
0
KBIPE4
KBEDG4
IRQPE
ACFGT
0
ADR4
3
PTAD3
PTADD3
PTBD3
PTBDD3
—
—
KBF
KBIPE3
KBEDG3
IRQF
—
0
ADR3
2
PTAD2
PTADD2
PTBD2
PTBDD2
—
—
KBACK
KBIPE2
KBEDG2
IRQACK
ADCH
—
0
ADR2
1
PTAD1
PTADD1
PTBD1
PTBDD1
—
—
KBIE
KBIPE1
KBEDG1
IRQIE
—
ADR9
ADR1
Bit 0
PTAD0
PTADD0
PTBD0
PTBDD0
—
—
KBMOD
KBIPE0
KBEDG0
IRQMOD
—
ADR8
ADR0
MC9S08QG8 and MC9S08QG4 Data Sheet, Rev. 5
Freescale Semiconductor
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