SNC710

16-bit Voice Engine

4.2 Memory Mapping

The SNC710 provides totally 24-bit address for mask ROM addressing. The whole

ROM area is divided into 8 pages, each page’s addressing ability is 32M bits (2M

words). The first ROM page is reserved for system. We built-in 32K words high speed

ROM internally for Voice decompressed algorithm. The actual addressing capability

free for user is 224M bits (14M words). The memory mapping of external mask ROM is

shown as bellow:

Reserved for System

Free for user

0x0200000

0x0FFFFFF

14M words

(224M bits)

32K words

(inside SNC710)

2M words

(32M bits)

0x0007FFF

0x0000000

0x0008000

0x01FFFFF

Table-1

4.3 System Clock

The system clock source also can be selected from 16MHZ Rosc. For the ROSC, user

should connect two resistors in the pin “XIN” and “XOUT” instead of 16MHZ crystal.

Beside, the clock source select pin “CKSEL” also should be connected to VDD for

ROSC. In order to get an accurate system clock by ROSC, the real time clock

source is recommended to connect a 32768HZ crystal for system clock

calibration.

R1

75K

R2

110K

XOUT

XIN

LXIN

38

39

43

LOUT 44

Ver. 1.3

April 3, 2003

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