Renesas CPU Board M3A-HS19 Bedienungsanleitung PDF herunterladen (Seite 9)

SH7285/SH7286 USB Function Module

USB to Serial Conversion Application Note

USB Function (Hardware)

Receives a command in EP0S

Processed by hardware

automatically?

Completed

Sets the setup request

receive complete flag

Clears the setup request

receive complete flag

Acquires a USB command

Sets the EP0S read complete flag

EP0sRDFN = 1

GetPacket

Class-specific

command?

DecComCommands

Standard command

to be handled?

Prepares GetDescriptor data

Class-specific command

to be handled?

Sets the state as STALL

State is STALL?

Transfer direction?

Sets the state as TRANS_IN

Sets the state as TRANS_OUT

Yes

Yes

No

No

Yes

No

Yes

No

Sets the interrupt enable bit

for control IN transfer

EP0iTS = EP0oTS = 1

Sets the interrupt enable bit

for control OUT transfer

EP0iTS = EP0oTS = EP0iTR = 1

Writes data in FIFO

PutPacket

Interrupt completed

Yes

No

IN (Device to host)

OUT (Host to device)

Disables interrupt

Sets STALL

USBEPSTL/EP0STL = 1

DecStandardCommand

ActControl handles

subsequently

Hardware processes each

stage automatically.

Decided by bit 6 and

5 in bmRequest

- Set Line Coding,

- Set Control Line State,

- Send Break

- Get line Coding

Only these commands are

decided to be handled.

Only GetDescriptor

command is decided

to be handled.

EpInfo[0].PresentState = STALL

EpInfo[0].PresentState

is STALL?

Decided by bit 7 in

bmRequest

Executes the ActControl

function in the USBIFR0

interrupt handler.

Interrupt started

ActControl started

Receives the EP0 setup token

Completed

Sample Program (Software)

(USBIFR0 interrupt)

USBIFR0/SETUPTS

interrupt

Figure 2.6 Setup Stage

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