
CY7C63310
CY7C638xx
Document 38-08035 Rev. *I
Page 56 of 74
The three data buffers used to hold data for both IN and OUT transactions. Each data buffer is 8 bytes long.
The reset values of the Endpoint Data Registers are unknown.
Unlike past enCoRe parts the USB data buffers are only accessible in the I/O space of the processor.
22.0
USB Mode Tables
Mode Column
The 'Mode' column contains the mnemonic names given to the
modes of the endpoint. The mode of the endpoint is deter-
mined by the four-bit binaries in the 'Encoding' column as
discussed below. The Status IN and Status OUT represent the
status IN or OUT stage of the control transfer.
Encoding Column
The contents of the 'Encoding' column represent the Mode
Bits [3:0] of the Endpoint Mode Registers (
Table 21-3
and
Table 21-4
). The endpoint modes determine how the SIE
responds to different tokens that the host sends to the
endpoints. For example, if the Mode Bits [3:0] of the Endpoint
0 Mode Register are set to '0001', which is NAK IN/OUT mode,
the SIE will send an ACK handshake in response to SETUP
tokens and NAK any IN or OUT tokens.
SETUP, IN, and OUT Columns
Depending on the mode specified in the 'Encoding' column,
the 'SETUP', 'IN', and 'OUT' columns contain the SIE's
responses when the endpoint receives SETUP, IN, and OUT
tokens, respectively.
A 'Check' in the Out column means that upon receiving an
OUT token the SIE checks to see whether the OUT is of zero
length and has a Data Toggle (Data1/0) of 1. If these condi-
tions are true, the SIE responds with an ACK. If any of the
above conditions is not met, the SIE will respond with either a
STALL or Ignore.
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Default
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
Unknown
The Endpoint 2 buffer is comprised of 8 bytes located at address 0x60 to 0x67
Table 21-7. Endpoint 2 Data (EP2DATA) [0x60-0x67] [R/W]
(continued)
Mode
DISABLE
Encoding
0000
SETUP
Ignore
IN
OUT
Ignore
Comments
Ignore
Ignore all USB traffic to this endpoint. Used by Data and
Control endpoints
NAK IN and OUT token. Control endpoint only
STALL IN and ACK zero byte OUT. Control endpoint only
STALL IN and OUT token. Control endpoint only
STALL OUT and send zero byte data for IN token. Con-
trol endpoint only
ACK the OUT token or send zero byte data for IN token.
Control endpoint only
Respond to IN data or Status OUT. Control endpoint only
NAK IN/OUT
STATUS OUT ONLY
STALL IN/OUT
STATUS IN ONLY
0001
0010
0011
0110
Accept
Accept
Accept
Accept
NAK
STALL
STALL
TX0 byte
NAK
Check
STALL
STALL
ACK OUT – STATUS
IN
ACK IN – STATUS
OUT
1011
Accept
TX0 byte
ACK
1111
Accept
TX Count
Check
NAK OUT
1000
1001
Ignore
Ignore
Ignore
Ignore
NAK
ACK
Send NAK handshake to OUT token. Data endpoint only
This mode is changed by the SIE to mode 1000 on is-
suance of ACK handshake to an OUT. Data endpoint
only
STALL the OUT transfer
Send NAK handshake for IN token. Data endpoint only
This mode is changed by the SIE to mode 1100 after
receiving ACK handshake to an IN data. Data endpoint
only
STALL the IN transfer. Data endpoint only
ACK OUT (STALL = 0)
ACK OUT (STALL = 1)
NAK IN
ACK IN (STALL = 0)
1001
1100
1101
Ignore
Ignore
Ignore
Ignore
NAK
TX Count
STALL
Ignore
Ignore
ACK IN (STALL = 1)
1101
Ignore
STALL
Ignore
Reserved
Reserved
Reserved
Reserved
Reserved
0101
0111
1010
0100
1110
Ignore
Ignore
Ignore
Ignore
Ignore
Ignore
Ignore
Ignore
Ignore
Ignore
Ignore
Ignore
Ignore
Ignore
Ignore
These modes are not supported by SIE. Firmware must
not use this mode in Control and Data endpoints