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2 functions of data buffer – NEC PD17062 User Manual

Page 90

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90

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PD17062

10.2 FUNCTIONS OF DATA BUFFER

The data buffer provides the following two functions:

(1) Read constant data in program memory (to reference tables)

(2) Transfer data to and from peripheral hardware

Fig. 10-3 shows the relationship between the data buffer, peripheral hardware, and memory.

Table referencing is described in Section 10.3, and the peripheral hardware is described in Sections 10.4

to 10.6.

Fig. 10-3 Relationship Between Data Buffer, Peripheral Hardware, and Memory

01H

02H

03H

04H

05H-08H

40H

41H

Peripheral address

Data buffer

Internal

Table referencing

Peripheral hardware

Image display controller (IDC)

A/D converter

Serial interface

Horizontal synchronizing signal
counter

6-bit D/A converter

Address register (AR)

PLL frequency synthesizer

Program memory

(ROM)

Constant data