|colspan=3|NOT USED||M||L3||L2||L1||L0
|-
|cospancolspan=3|||amplitude "mode"||cospan=4|4-bit "fixed" amplitude level
|}
The frequency of the envelope is obtained in the PSG by first counting down the input clock by 256, then by furthur counting down the result of the programmed 16-bit Envelope Period value. This 16-bit value is obtained in the PSG by combining the contents of the Envelope Coarse and Fine Tune registers, as illustrated in the following:
{|{{Prettytable|width: 700px; font-size: 2em;}}|colspan=8|'''Envelope Coarse Tune Register R14 '''||colspan=8|'''Envelope Fine Tune Register R13 '''|-|B7 ||B6 ||B5 ||B4 ||B3 ||B2 ||B1 ||B0 ||B7 ||B6 ||B5 ||B4 ||B3 ||B2 ||B1 ||B0 |-|EP15 ||EP14 ||EP13 ||EP12 ||EP11 ||EP10 ||EP9 ||EP8 ||EP7 ||EP6 ||EP5 ||EP4 ||EP3 ||EP2 ||EP1 ||EP0 |-|colspan=16|16-bit Envelope Period (EP) to Envelope Generator |}
== ENVELOPE SHAPE/CYCLE CONTROL (Register R15) ==