Specifications

CY7C67200
Document Number: 38-08014 Rev. *J Page 89 of 93
9. Peripheral Short Packet Issue
■ Problem Definition
When a SIE is configured as a peripheral, the SUSBx_RECEIVE function does not invoke the callback function when it receives
a short packet.
■ Parameters Affected
SIEx Endpoint x Interrupt (Interrupt 32-47).
■ Trigger Conditions
This issue is seen when a SIE is configured as a peripheral during an OUT data transfer when the host sends a zero length or
short packet. If this occurs the BIOS will behave as if a full packet was received and will continue to accept data until the Device n
Endpoint n Count Register value is satisfied.
■ Scope of Impact
All peripheral functions are susceptible to this as it is a normal occurrence with USB traffic.
■ Workaround
To fix this problem the SIEx Endpoint x Interrupt must be replaced for any peripheral endpoint that is configured as an OUT endpoint.
1. Acquire the file called susb1.s from Cypress Support or by downloading a newer version of the frameworks that has had
this fix applied and includes susb1.s.
2. Modify fwxcfg.h in your project to have the following flags and define/undef the fix for the endpoints you are using:
#define FIX_USB1_EP1
#define FIX_USB1_EP2
#undef FIX_USB1_EP3
#undef FIX_USB1_EP4
#undef FIX_USB1_EP5
#undef FIX_USB1_EP6
#undef FIX_USB1_EP7
#undef FIX_USB2_EP1
#undef FIX_USB2_EP2
#undef FIX_USB2_EP3
#undef FIX_USB2_EP4
#undef FIX_USB2_EP5
#undef FIX_USB2_EP6
#undef FIX_USB2_EP7
3. Add the new susb1.s to the included assembly source files in the make file.
For example: ASM_SRC := startup.s isrs.s susb1.s
4. Add usb_init somewhere in the startup code. This will likely be in fwxmain.c as demonstrated below:
void fwx_program_init(void)
{
void usb_init(); /* define the prototype */
usb_init();
fwx_init(); /* Initialize everything in the base framework. */
}
5. Build the project using the modified make file.
■ Fix Status
The ROM version of the BIOS will be updated during any future silicon rolls. No current roll of the part currently exists.
10.Data Toggle Corruption Issue