Maxim-integrated MAXQ610 Manual de usuario descargar pdf (Pagina 13)

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MAXQ610 User’s Guide

2.5.1 Memory Mapping Into Data Space

The MAXQ610 maps program memory into data space from 0000h to 7FFFh. The selection of physical program

memory page or pages to be logically mapped to data space is determined by the CDA1 and CDA0 bits, as shown in

Table 2-2. Note that CDA1 is fixed at 0.

Figure 2-3 summarize the default memory maps for this memory structure. The WBSn bits of the MAXQ610 default to

word access mode (WBSn = 1).

The upper half of the data memory map (8000h to FFFFh) is the logical area for the utility ROM when accessed as

data. Executing code from the utility ROM allows the user to map the program memory to 8000h to FFFFh by properly

selecting the CDA bits.

Figure 2-4 and 2-5 illustrate the effects of the CDA bits.

Figure 2-3. MAXQ610 Memory Map (64KB Program Space)

Table 2-2. CDA Bits to Access Program Space as Data

PROGRAM

SPACE

87FFh

7FFFh

0000h

8000h

2K x 16

UTILITY ROM

2K x 8

DATA SRAM

1K x 16

DATA SRAM

32K x 16

PROGRAM FLASH

MASKED ROM

DATA SPACE

(BYTE MODE)

DATA SPACE

(WORD MODE)

0000h

07FFh

0000h

03FFh

CDA[1:0] SELECTED PAGE IN BYTE MODE SELECTED PAGE IN WORD MODE

00 P0 P0 and P1

01 P1 P0 and P1

1 2 ... 8 9 10 11 12 13 14 15 16 17 18 ... 202 203

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Maxim-integrated MAXQ610 Manual de usuario Pagina 13