Cypress specifications CY7C68300C/CY7C68301C CY7C68320C/CY7C68321C, Sysirq, USB High-Speed

CY7C68300C/CY7C68301C

CY7C68320C/CY7C68321C

SYSIRQ

The SYSIRQ pin provides a way for systems to request service from host software by using the USB Interrupt pipe on endpoint 1 (EP1). If the AT2LP has no pending interrupt data to return, USB interrupt pipe data requests are NAKed. If pending data is available, the AT2LP returns 16 bits of data. This data indicates whether AT2LP is operating in high-speed or full-speed, whether the AT2LP is reporting self-powered or bus-powered operation, and the states of any GPIO pins that are configured as inputs. GPIO pins can be individually set as

inputs or outputs, with byte 0x09 of the configuration data. The state of any GPIO pin that is not set as an input is reported as ‘0’ in the EP1 data.

Table 3 gives the bitmap for the data returned on the interrupt pipe and Figure 8 depicts the latching algorithm incorporated by the AT2LP.

The SYSIRQ pin must be pulled LOW if HID functionality is used. Refer to “HID Functions for Button Controls” on page 15 for more details on HID functionality.

Table 3. Interrupt Data Bitmap

			EP1 Data Byte 1									EP1 Data Byte 0
7	6	5		4	3	2	1	0	7	6	5		4	3	2	1	0
RESERVED	RESERVED	RESERVED		RESERVED	RESERVED	RESERVED	USB High-Speed	VBUS Powered	RESERVED	RESERVED	GPIO[5]		GPIO[4]	GPIO[3]	GPIO[2]	GPIO[1]	GPIO[0]

Document 001-05809 Rev. *A Page 12 of 42

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