Figure 15.23 Automatic Stall By Usb Function Module - Hitachi H8S/2215 Series Hardware Manual

(1) Transition from normal operation to stall
(1-1)
STALL handshake
(2) When transaction is performed when internal status bit is set
(2-1)
Transaction request
(2-2)
STALL handshake
(3) When Clear Feature is sent before transaction is performed
(3-1)
Clear Feature command

Figure 15.23 Automatic Stall by USB Function Module

Rev. 3.0, 10/02, page 512 of 686
USB function module
Internal status bit
0 → 1
To (2-1) or (3-1)
Internal status bit
1
Internal status bit
1
Stall status maintained
Internal status bit
1 → 0
Normal status restored
1. In case of USB
specification
EPnSTL
violation, USB
0
function module
stalls endpoint
automatically.
1. Receive IN/OUT
token from the host
EPnSTL
2. Internal status bit
0
has been set to 1
3. EPnSTL not
referenced
4. No change internal
status bit
1. Transmit STALL
EPnSTL
handshake
0
1. Clear the internal
status bit to 0
EPnSTL
2. No change in
0
EPnSTL