Cypress CY7C67300 Manual De Usuario

Document #: 38-08015 Rev. *J

Page 42 of 99

underflow and the Overflow and Underflow flags (bits 11 and 10
respectively) must be checked to determine which event
occurred.

 An overflow or underflow condition occurred 

 An overflow or underflow condition did not occur 

 (Bit 4)

The Setup Flag bit indicates that a setup packet was received.
In device mode setup packets are stored at memory location
0x0300 for Device 1 and 0x0308 for Device 2. Setup packets are
always accepted regardless of the Direction Select and Arm
Enable bit settings as long as the Device n EP n Control register
Enable bit is set.

 Setup packet was received

 Setup packet was not received

 (Bit 3)

The Sequence Flag bit indicates whether the last data toggle
received was a DATA1 or a DATA0. This bit has no effect on
receiving data packets; sequence checking must be handled in
firmware.

 DATA1 was received

 DATA0 was received

 (Bit 2)

The Timeout Flag bit indicates whether a timeout condition
occurred on the last transaction. On the device side, a timeout
can occur if the device sends a data packet in response to an IN
request but then does not receive a handshake packet in a
predetermined time. It can also occur if the device does not
receive the data stage of an OUT transfer in time.

 Timeout occurred

 Timeout condition did not occur

 (Bit 2)

The Error Flag bit is set if a CRC5 and CRC16 error occurs, or if
an incorrect packet type is received. Overflow and underflow are
not considered errors and do not affect this bit.

 Error occurred

 Error did not occur

 (Bit 0)

The ACK Flag bit indicates whether the last transaction was
ACKed.

 ACK occurred

 ACK did not occur

■

Device n Endpoint 0 Count Result Register [Device 1: 0x0208 Device 2: 0x0288]

■

Device n Endpoint 1 Count Result Register [Device 1: 0x0218 Device 2: 0x0298]

■

Device n Endpoint 2 Count Result Register [Device 1: 0x0228 Device 2: 0x02A8]

■

Device n Endpoint 3 Count Result Register [Device 1: 0x0238 Device 2: 0x02B8]

■

Device n Endpoint 4 Count Result Register [Device 1: 0x0248 Device 2: 0x02C8]

■

Device n Endpoint 5 Count Result Register [Device 1: 0x0258 Device 2: 0x02D8]

■

Device n Endpoint 6 Count Result Register [Device 1: 0x0268 Device 2: 0x02E8]

■

Device n Endpoint 7 Count Result Register [Device 1: 0x0278 Device 2: 0x02F8]

 

The Device n Endpoint n Count Result register contains the size
difference in bytes between the Endpoint Count specified in the
Device n Endpoint n Count register and the last packet received.
If an overflow or underflow condition occurs, that is, the received
packet length differs from the value specified in the Device n

Endpoint n Count register, the Length Exception Flag bit in the
Device n Endpoint n Status register is set. The value in this
register is only valued when the Length Exception Flag bit is set
and the Error Flag bit is not set; both bits are in the Device n
Endpoint n Status register.

Result...

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

X

X

X

X

X

X

X

X

...Result

R/W

R/W

R/W

R/W

R/W

R/W

R/W

R/W

X

X

X

X

X

X

X

X