CY7C63413C
CY7C63513C
CY7C63613C
Document #: 38-08027 Rev. *B Page 21 of 32
Truth Tables
The ‘In’ column represents the SIE’s response to the token
type.
A disabled endpoint will remain such until firmware changes it,
and all endpoints reset to disabled.
Any Setup packet to an enabled and accepting endpoint will
be changed by the SIE to 0001 (NAKing). Any mode which
indicates the acceptance of a Setup will acknowledge it.
Most modes that control transactions involving an ending ACK
will be changed by the SIE to a corresponding mode which
NAKs follow on packets.
A Control endpoint has three extra status bits for PID (Setup,
In and Out), but must be placed in the correct mode to function
as such. Also a non-Control endpoint can be made to act as a
Control endpoint if it is placed in a non appropriate mode.
A ‘check’ on an Out token during a Status transaction checks
to see that the Out is of zero length and has a Data Toggle
(DTOG) of 1.
Table 28.USB Register Mode Encoding
Mode Encoding Setup In Out Comments
Disable 0000 ignore ignore ignore Ignore all USB traffic to this endpoint
Nak In/Out 0001 accept NAK NAK Forced from Set-up on Control endpoint, from modes other
than 0000
Status Out Only 0010 accept stall check For Control endpoints
Stall In/Out 0011 accept stall stall For Control endpoints
Ignore In/Out 0100 accept ignore ignore For Control endpoints
Isochronous Out 0101 ignore ignore always Available to low speed devices, future USB spec
enhancements
Status In Only 0110 accept TX 0 stall For Control Endpoints
Isochronous In 0111 ignore TX cnt ignore Available to low speed devices, future USB spec
enhancements
Nak Out 1000 ignore ignore NAK An ACK from mode 1001 --> 1000
Ack Out 1001 ignore ignore ACK This mode is changed by SIE on issuance of ACK --> 1000
Nak Out - Status In 1010 accept TX 0 NAK An ACK from mode 1011 --> 1010
Ack Out - Status In 1011 accept TX 0 ACK This mode is changed by SIE on issuance of ACK --> 1010
Nak In 1100 ignore NAK ignore An ACK from mode 1101 --> 1100
Ack In 1101 ignore TX cnt ignore This mode is changed by SIE on issuance of ACK --> 1100
Nak In - Status Out 1110 accept NAK check An ACK from mode 1111 --> 1110 NAck In - Status Out
Ack In - Status Out 1111 accept TX cnt Check This mode is changed by SIE on issuance of ACK -->1110
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