Cypress EZ-OTG CY7C67200 用户手册
CY7C67200
Document #: 38-08014 Rev. *G
Page 33 of 78
Device n Endpoint n Count Result Register [R/W]
• 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]
Figure 34. Device n Endpoint n Count Result Register
Register Description
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 will be set.
The value in this register is only considered 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.
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 will be set.
The value in this register is only considered 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.
The Device n Endpoint n Count Result register is a memory
based register that must be initialized to 0x0000 before USB
Device operations are initiated. After initialization, this register
must not be written to again.
based register that must be initialized to 0x0000 before USB
Device operations are initiated. After initialization, this register
must not be written to again.
Result (Bits [15:0])
The Result field contains the differences in bytes between the
received packet and the value specified in the Device n
Endpoint n Count register. If an overflow condition occurs,
Result [15:10] is set to ‘111111’, a 2’s complement value
indicating the additional byte count of the received packet. If
an underflow condition occurs, Result [15:0] indicates the
excess byte count (number of bytes not used).
received packet and the value specified in the Device n
Endpoint n Count register. If an overflow condition occurs,
Result [15:10] is set to ‘111111’, a 2’s complement value
indicating the additional byte count of the received packet. If
an underflow condition occurs, Result [15:0] indicates the
excess byte count (number of bytes not used).
Reserved
All reserved bits must be written as ‘0’.
Bit #
15
14
13
12
11
10
9
8
Field
Result...
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Default
X
X
X
X
X
X
X
X
Bit #
7
6
5
4
3
2
1
0
Field
...Result
Read/Write
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Default
X
X
X
X
X
X
X
X