CY7C67300_13 Datasheet, PDF (32/112 Pages) Cypress Semiconductor – EZ-Host™ Programmable Embedded USB Host and Peripheral Controller with Automotive AEC Grade Support

CY7C67300
Register Description
The Host n Count register is used to hold the number of bytes
(packet length) for the current transaction. The maximum packet
length is 1023 bytes in ISO mode. The Host Count value is used
to determine how many bytes to transmit, or the maximum
number of bytes to receive. If the number of received bytes is
greater then the Host Count value then an overflow condition is
flagged by the Overflow bit in the Host n Endpoint Status register.
Port Select (Bit 14)
The Port Select bit selects which of the two active ports is
selected and is summarized in Table 51.
1: Port 1B or Port 2B is enabled
0: Port 1A or Port 2A is enabled
Table 51. Port Select Definition
Port Select
0
1
Host/Device 1
Active Port
A
B
Host/Device 2
Active Port
A
B
Count (Bits [9:0])
The Count field sets the value for the current transaction data
packet length. This value is retained when switching between
host and device mode, and back again.
Reserved
Write all reserved bits with ’0’.
Host n Endpoint Status Register [R]
■ Host 1 Endpoint Status Register 0xC086
■ Host 2 Endpoint Status Register 0xC0A6
Table 52. Host n Endpoint Status Register
Bit #
15
Field
Read/Write
-
Default
0
14
13
Reserved
-
-
0
0
12
11
10
9
8
Overflow
Flag
Underflow
Flag
Reserved
-
R
R
-
-
0
0
0
0
0
Bit #
7
Stall
Flag
Field
Read/Write
R
Default
0
6
NAK
Flag
R
0
5
Length
Exception
Flag
R
0
4
Reserved
-
0
3
Sequence
Status
R
0
2
Timeout
Flag
R
0
1
Error
Flag
R
0
0
ACK
Flag
R
0
Register Description
The Host n Endpoint Status register is a read only register that
provides status for the last USB transaction.
Overflow Flag (Bit 11)
The Overflow Flag bit indicates that the received data in the last
data transaction exceeded the maximum length specified in the
Host n Count register. The Overflow Flag must be checked in
response to a Length Exception signified by the Length
Exception Flag set to ‘1’.
1: Overflow condition occurred
0: Overflow condition did not occur
Underflow Flag (Bit 10)
The Underflow Flag bit indicates that the received data in the last
data transaction was less than the maximum length specified in
the Host n Count register. The Underflow Flag must be checked
in response to a Length Exception signified by the Length
Exception Flag set to ‘1’.
1: Underflow condition occurred
0: Underflow condition did not occur
Stall Flag (Bit 7)
The Stall Flag bit indicates that the peripheral device replied with
a Stall in the last transaction.
1: Device returned Stall
0: Device did not return Stall
NAK Flag (Bit 6)
The NAK Flag bit indicates that the peripheral device replied with
a NAK in the last transaction.
1: Device returned NAK
0: Device did not return NAK
Length Exception Flag (Bit 5)
The Length Exception Flag bit indicates that the received data in
the data stage of the last transaction does not equal the
maximum Host Count specified in the Host n Count register. A
Length Exception can either mean an overflow or underflow and
the Overflow and Underflow flags (bits 11 and 10, respectively)
must be checked to determine which event occurred.
1: An overflow or underflow condition occurred
0: An overflow or underflow condition did not occur
Document Number: 38-08015 Rev. *L
Page 32 of 112