Rejunity’s Designs

Two designs on this GFMPW-1 submission were contributed by Rejunity. More information on these can be found at these links:

SN76489

AY8913

Pinouts

The pinouts of these projects on this particular chip are:

SN76489

images/pinoutsn.drawio.png
Table 10 Pin description

Pin #

Name

Type

Summary

mprj_io[0]

RSTD

I

Active low design reset

mprj_io[12:5]

D[7:0]

I

Data Inputs

mprj_io[16:13]

PWM[3:0]

O

Individual PWM audio output for each channel

mprj_io[17]

PWM4

O

PWM audio output for mixed audio from all channels

mprj_io[19]

WE

I

Active low Write Enable

mprj_io[22]

DAC DAT

O

Serial Data for external DAC (DAC7611 or similar)

mprj_io[23]

DAC LE

O

Active low Latch Enable for external DAC

mprj_io[24]

DAC CLK

O

Serial Clock for external DAC

mprj_io[32:25]

RAW[7:0]

O

Raw digital audio sample output with 8-bit resolution

AY8913

images/pinoutay.drawio.png
Table 11 Pin description

Pin #

Name

Type

Summary

mprj_io[0]

RSTD

I

Active low design reset

mprj_io[12:5]

D[7:0]

I

Data Inputs

mprj_io[15:13]

PWM[2:0]

O

Individual PWM audio output for each channel

mprj_io[16]

PWM4

O

PWM audio output for mixed audio from all channels

mprj_io[19]

BDIR

I

Bus control signal

mprj_io[20]

BC1

I

Bus control signal

mprj_io[22]

DAC DAT

O

Serial Data for external DAC (DAC7611 or similar)

mprj_io[23]

DAC LE

O

Active low Latch Enable for external DAC

mprj_io[24]

DAC CLK

O

Serial Clock for external DAC

mprj_io[32:25]

RAW[7:0]

O

Raw digital audio sample output with 8-bit resolution

Custom Settings

Both designs use the first two bits of reg_mprj_settings to set a clock divider for the whole design.

SN76489

Table 12 Clock divider options

reg_mprj_settings value

Setting

0

Div by 16

1

Div by 1

2

Div by 128

AY8913

Table 13 Clock divider options

reg_mprj_settings value

Setting

0

Div by 8

1

Div by 1

2

Div by 128