Figure 405. Trdt Max Timing Case; Otg Programming Model - STMicroelectronics STM32F405 Reference Manual

USB on-the-go full-speed (OTG_FS)
tkn_rcvd
dsynced_tkn_rcvd
spr_read
spr_addr
spr_rdata
srcbuf_push
srcbuf_rdata
34.17.8

OTG programming model

The OTG_FS controller is an OTG device supporting HNP and SRP. When the core is
connected to an "A" plug, it is referred to as an A-device. When the core is connected to a
"B" plug it is referred to as a B-device. In host mode, the OTG_FS controller turns off V
to conserve power. SRP is a method by which the B-device signals the A-device to turn on
V power. A device must perform both data-line pulsing and V
BUS
detect either data-line pulsing or V
device negotiates and switches to host role. In Negotiated mode after HNP, the B-device
suspends the bus and reverts to the device role.
1362/1731

Figure 405. TRDT max timing case

0ns
1 2
HCLK
PCLK
DocID018909 Rev 11
50ns 100ns
3 4
A1
5 Clocks
pulsing for SRP. HNP is a method by which the B-
BUS
150ns 200ns
5 6 7
D1
D1
pulsing, but a host can
BUS
RM0090
8
ai15680
BUS