USB0 built-in DMA controller burst size can't be changed

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

USB0 built-in DMA controller burst size can't be changed

685 Views
lpcware
NXP Employee
NXP Employee
Content originally posted in LPCWare by Pavel Boldin on Fri Jul 11 11:54:52 MST 2014
Hello everyone,

There is a register 'BURSTSIZE' among the controlling registers of the USB0 Host controller. Its purpose according to the user manual UM10503 is to change burst sizes of the DMA master bursts.

However, I'm unable to change this register value neither through the JTAG nor directly from the CPU:
> mdw 0x40006160          
0x40006160: 00001010
> mww 0x40006160 0x101
> mdw 0x40006160     
0x40006160: 00001010

Here 'mdw' means 'memory dump word' and 'mww' means 'memory write word'. (These are OpenOCD commands)

Resetting the controller is not helping either:
> mww 0x40006140 0x2
> mdw 0x40006140   
0x40006140: 00080000
> mdw 0x40006160     
0x40006160: 00001010
> mww 0x40006160 0x101
> mdw 0x40006160     
0x40006160: 00001010

(Commands are the same)

What can be a problem here?
Labels (1)
0 Kudos
Reply
1 Reply

675 Views
lpcware
NXP Employee
NXP Employee
Content originally posted in LPCWare by alexn on Fri Feb 06 02:10:20 MST 2015
Same problem here. I'm using IAR Embedded Workbench and can't change this register's value by writing it or by editing it manually during debug. Segger J-Mem can't change it's value too. At the same time have no problem with writing BURSTSIZE of USB1. Is there some algo required for this operation or is it's value fixed?
0 Kudos
Reply