From 1ff545434f2070ac461bbf851f44d63538179195 Mon Sep 17 00:00:00 2001 From: arc Date: Sun, 3 Aug 2025 13:41:47 -0600 Subject: [PATCH] vault backup: 2025-08-03 13:41:47 --- notes/USB.md | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/notes/USB.md b/notes/USB.md index 607e216..3a13d9b 100644 --- a/notes/USB.md +++ b/notes/USB.md @@ -12,4 +12,12 @@ USB devices are one of the following: # Interconnects # Protocol -A Universal Serial bus is strictly a *polled* bus, meaning the \ No newline at end of file +A Universal Serial bus is strictly a *polled* bus, meaning the host controller initiates every data transfer. + +Most bus transactions involve the transmission of up to three packets. +1. The token packet +> Each transaction begins when the host, on a scheduled basis, sends a USB packet describing the type and direction of a transaction, the USB device address, and endpoint number. +2. The data packet +> Depending on the di +3. The handshake packet +> The destination, in general, responds to a handshake packet indicating whether the transfer was successful. \ No newline at end of file