topic Re: MCF52223 USB Device Controller. in ColdFire/68K Microcontrollers and Processors

MCF52223 USB Device Controller.

SetAlias — Fri, 07 Dec 2007 17:47:56 GMT

Hi All,

Presently Iam porting our USB stack on MCF52223 Coldfire micro controller.Can anybody knows the Max packet size of Each Endpoint from EP0 - EP15. No information in reference manual ....

Re: MCF52223 USB Device Controller.

Technoman64 — Sat, 08 Dec 2007 03:35:27 GMT

When I puchased MC52223 demo board a softcover book came with the kit that is filled with a lot of valuable information. I will look when I get chance and see if this listed. It has an entire chapter dedicated to the USB interface with examples. I will also post the book title.

Re: MCF52223 USB Device Controller.

Technoman64 — Sat, 08 Dec 2007 04:00:01 GMT

Here is what is listed.

Full set of endpoints EP0-EP15 is only available when operating as a Device. The number of endpoints available is limited when operating as Host or OTG.

Isochronous Transfer - Available only in Full and High Speed modes with a maxium payload size of 1024 Bytes.

Interrupt Transfer - 8 bytes for Low speed, 64 bytes for Full speed, 1024 bytes for High speed.

Bulk Transfer - Full speed supports packet sizes of 8,16,32, or 64 bytes. High speed supports a packet size of up to 512 bytes.

Not sure if this the info you need.

Title of book is "Coldfire Microprocessors & Microcontrollers"

ISBN 0-9762973-0-2 AMT Publishing and was written by Freescale Engineers form what I can tell.

Re: MCF52223 USB Device Controller.

SetAlias — Tue, 11 Dec 2007 16:00:12 GMT

Thanks Technoman, the suggested book name has information about Endpoint Max packet size according to the USB specification.

If we observe the BD Byte format in which bit 16:26(10 bits = 2 pow 10 = 1024 bytes ,max) is the byte count field which indicates the data recieved or transfered length.So when host wants to send max data then it has to send Max.packet size data, if Host send more data then BUS Error will occure(USB protocol Error). More over if Device software sets data length more than byte count field (Max. packet size) then which causes the Device in unpredictable state.

So finally the Endpoint Max. Packet size = byte count should be set according to the USB Specification depending on Low, Full and High speed Devices.