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Node 316

This node has two functions. First it provides millisecond timer for USB frames. Second function is to continuously read signal from oscillator in 417 (via wire in 416); this is important because at least one node must be ready to read clock signal from 417 otherwise the oscillator would halt.

Source code

usb node 416 node 216 node 316
316 timer
go 00 23999 for @ unext
@b - 4000 dr and if a down a! dup ! a! then go ; 0A

init up a! io b! go ; 0E

4 d 8 r 0 u ether

Definitions

go
Read 24000 times from UP, then continue code execution. At pulse rate of 24 Mpulses/s from node 416 the following code is executed once in every millisecond.

Read IO and test if node 216 is suspended in DOWN read. If so, send a signal to 216 and return to go. This provides one millisecond timing pulse train to node 216 when needed.

init
Set registers A and B, and jump to go.

Description