DF2211NP24V Renesas Technology / Hitachi Semiconductor, DF2211NP24V Datasheet - Page 573

• Manufacturer Part Number: DF2211NP24V
• Description: H8S/2200 Series, 2212 Group, USB, RTC, HSS TNP-64B; Vcc= 2.7 to 3.6 volts, Temp= -20 to 75 C; Package: PVQN0064LB-A
• Manufacturer: Renesas Technology / Hitachi Semiconductor

(3) Automatic Stall by USB Function Module
(1) Transition from normal operation to stall
(2) When transaction is performed whill internal status bit is set
(3) When Clear Feature is sent before transaction is performed
When a stall setting is made with the Set Feature command, when the information of this
module differs from that returned to the host by the Get Descriptor, or in the event of a USB
specification violation, the USB function module automatically sets the internal status bit for
the corresponding endpoint without regarding to EPnSTL, and returns a stall handshake (1-1 in
figure 14.21).
Once an internal status bit is set, it remains set until cleared by a Clear Feature command from
the host, without regarding to EPnSTL. After a bit is cleared by the Clear Feature command,
EPnSTL is referred (3-1 in figure 14.21). The USB function module continues to return a stall
handshake while the internal status bit is set, since the internal status bit is set even if a
transaction is executed for the corresponding endpoint (2-1 and 2-2 in figure 14.21). To clear a
stall, therefore, the internal status bit must be cleared with a Clear Feature command (3-1 in
figure 14.21). If set by the firmware, EPnSTL should also be cleared (2-1 in figure 14.21).
(2-2)
(3-1)
(1-1)
Stall handshake
(2-1)
Transaction request
Stall handshake
Clear Feature command
Figure 14.21 Automatic Stall by USB Function Module
Internal status bit
Internal status bit
Internal status bit
Internal status bit
0 → 1
1 → 0
1
1
Normal status restored
Stall status maintained
USB function module
To (2-1) or (3-1)
Rev.7.00 Dec. 24, 2008 Page 519 of 698
EPnSTL
EPnSTL
EPnSTL
EPnSTL
0
0
0
0
1. In case of USB
1. Receive IN/OUT
2. Internal status bit has
3. EPnSTL is not
4. No change internal
1. Transmit stall
1. Clear the internal
2. No change in
specification violation,
USB function module
stalls endpoint
automatically.
token from the host
been set to 1
referred to
status bit
handshake
status bit to 0
EPnSTL bit
REJ09B0074-0700