cy8c3446lti-075es2 Cypress Semiconductor Corporation., cy8c3446lti-075es2 Datasheet - Page 28

• Manufacturer Part Number: cy8c3446lti-075es2
• Description: Psoc? 3 Cy8c34 Family Errata Silicon Revision Es2
• Manufacturer: Cypress Semiconductor Corporation.

45. USB Suspend
46. USBIO Used as GPIO
January 7, 2011
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PROBLEM DEFINITION
If USB is enabled and the chip enters hibernate or sleep mode the D+ and D- pins are both pulled high with
5 k resistors in violation of the USB specification for suspend mode.
PARAMETERS AFFECTED
NA
TRIGGER CONDITION(S)
USB interface enabled when the chip enters hibernate or sleep mode.
SCOPE OF IMPACT
For a high speed USB device in the USB suspend mode D+ must be pulled high with a 1.5 k resistor and
D- configured for high impedance. This errata causes both D+ and D- to be pulled high with 5 k resistors
when the device enters hibernate or sleep mode. Hibernate and sleep mode may not be entered if USB is
enabled to meet the USB bus specification. If USB is disabled on the device no errata exists.
WORKAROUND
The USB component in PSoC Creator implements the required workaround in the API to enter USB suspend
mode. The component workaround places the PSoC device into Alternate Active mode with all resources
disabled except USB to reduce current to the lowest possible level, and it properly configures the D+ and D-
pins for suspend mode. The use of Alternate Active mode verse Sleep or Hibernate for the workaround results
in an increase of 1.4 mA of current.
FIX STATUS
Silicon revision fix confirmed in production silicon
PROBLEM DEFINITION
The USBIO cannot be controlled using the GPIO port and pin registers.
TRIGGER CONDITION(S)
Use of USBIO as GPIO pins. Does not impact use of the pins for USB.
SCOPE OF IMPACT
Read and write of USBIO using port and pin registers has no effect.
WORKAROUND
Use the USB registers to control the I/O by setting the USB_USBIO_CR1 (0x6012) register bit 7 to bit banged
mode and using bit 4 and bit 5 to toggle data. Bit 0 and bit 1 should be used to read the status of the USBIO
pins.
FIX STATUS
Silicon revision fix confirmed in production silicon.
Document Number: 001-61136 Rev. *C
Errata Document
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PSoC
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3: CY8C34 Family
28
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