REV. M

Page 16

September 1998

AS3502

9) SEQUENCE CONTROL REGISTER 2

This register contains the frequency codes for the second three steps of the six tone cadence.

SC2

D7

D6

D5

D4

D3

D2

D1

D0

Name

0

0

Default

0

0

X

X

X

X

X

X

Bit No

Symbol

Name and Description

D7, D6

-

Not used; will be low during read

D5, D4

S61,S60

Cadence Step 6:

00:

No Tone

01:

Frequency/Volume Register 1 is selected

10:

Frequency/Volume Register 2 is selected

11:

Frequency/Volume Register 3 is selected

D3, D2

S51, S50

Cadence Step 5

00:

No Tone

01:

Frequency/Volume Register 1 is selected

10:

Frequency/Volume Register 2 is selected

11:

Frequency/Volume Register 3 is selected

D1, D0

S41, S40

Cadence Step 4

00:

No Tone

01:

Frequency/Volume Register 1 is selected

10:

Frequency/Volume Register 2 is selected

11:

Frequency/Volume Register 3 is selected

10) FREQUENCY CONTROL REGISTER 1

This register contains eight bits of the 10-bit coefficient of the first frequency.

F1

D7

D6

D5

D4

D3

D2

D1

D0

Name

F17

F16

F15

F14

F13

F12

F11

F10

Default

X

X

X

X

X

X

X

X

Bit No

Symbol

Name and Description

D7-D0

F17-F10

A 10-bit coefficient (X) written into this register and into bits D0 and D1 of V1 allows to

programme the first frequency from 3.9 Hz to 3996 Hz. The coefficient for a given

frequency can be calculated as:

X

=

f (Hz )* 256

1000

; X = ( 1…1023)

11) VOLUME CONTROL REGISTER 1

This register contains the remaining two bits of the first frequency coefficient and volume control data for pulse

density volume control of square waves.