UPD9971 datasheet(32/112 Pages) RENESAS

32 / 112 page

µPD9971

Data Sheet S17455EJ2V0DS

3.2.5 Initialization of serial interface

The SERINIT (D0) pin is an initialization signal for the serial I/F and is used for compulsory initialization of the serial

I/F during write/read continuous access. (Therefore, this pin is normally used at low level if compulsory initialization is

unnecessary)

The compulsory initialization operates only the serial I/F and is asynchronously performed by SCS = 1 and SERINIT

= 0. On the other hand the registers in the sound generator and chip control are not initialized. Therefore the serial I/F

wait for a new address to be input after initialization.

An example of this initialization signal is shown below.

Figure 3-11 Canceling Continuous Access Using SERINT (D0) Pin

(a) Write Access

TXD

SCLK

SCS

R/W

RXD

SERINIT

R/W

Hi-Z

Address

Hi-Z

The number of

times of data(n–1)

Waiting for

'Data 2' input

Initializing

serial I/F

Waiting for

address input

New command

Data 1

8 bits

(b) Read Access

TXD

SCLK

SCS

R/W

RXD

SERINIT

R/W

Hi-Z

Address

Hi-Z

The number of

times of data(n–1)

Initializing

serial I/F

Waiting for

address input

New command

Data 1

8 bits

From CPU

To CPU

Hi-Z

Remark

The initialization conditions in 3 / 4 -wire mode are the same.

UPD9971 Datasheet(PDF) 32 Page - Renesas Technology Corp

UPD9971 Datasheet(HTML) 32 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL