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1999 May 10 32
Philips Semiconductors Preliminary specification
Universal Serial Bus (USB) CODEC UDA1325
Reset value: gives the value of the bits after Power-on
reset. Bus reset: a ‘F’ indicates that the value of the bit is
not changed during a bus reset. a ‘T’ indicates that during
a bus reset, the bit is reset to its reset value.
Table 25
Data flow commands
Data flow commands are used to manage the data
transmission between the USB endpoints and the host.
Much of the data flow is initiated via the interrupt to the
microcontroller. The microcontroller uses these
commands to access the endpoint buffers and determine
whether the endpoint buffers have valid data.
R
EAD INTERRUPT REGISTER
Command: F4h.
Data: read 1 byte.
The read interrupt register command returns the value of
the interrupt register. Every time a packet is received or
transmitted, an interrupt will be generated and a flag
specific to the physical endpoint will be set in the interrupt
register. Reading the status of the endpoint will clear the
flag.
BIT DESCRIPTION
IsoOut ISO out endpoint can be
used
IsoIn ISO in endpoint can be
used
IntIsoOut allow interrupt from ISO
out endpoint
IntIsoIn allow interrupt from ISO in
endpoint
ErrorDebugMode Setting chip in debug
mode
AlwaysPLLClock the PLL clock must keep
on running
T T F F T T T T
IsoOut
IsoIn
IntIsoOut
IntIsoIn
ErrorDebugMode
AlwaysPLLClock
Reserved
Reserved
76543210
Bus Reset
11111100
Reset value
An interrupt is also generated after a bus reset. When the
interrupt register consists of all zeros, and an interrupt was
generated, there was a bus reset. The interrupt is cleared
when the interrupt register is read.
S
ELECT ENDPOINT
Command: 00h + endpoint index.
Data: optional read 1 byte.
The select endpoint command initializes an internal
pointer to the start of the selected buffer. Optionally, this
command can be followed by a data read. Bit 0 is low if the
buffer is empty and high if the buffer is full. There is one
command for every endpoint.
G
ET ENDPOINT STATUS
Command: 40h + endpoint index.
Data: read 1 byte.
The get endpoint status command is followed by one data
read that returns the status of the last transaction of the
selected endpoint. This command also resets the
corresponding interrupt flag in the interrupt register, and
clears the status, indicating that it was read. There is one
command for every endpoint.
0 0 0 0 0 0 0 0
Control OUT
Control IN
Endpoint 1 OUT
Endpoint 1 IN
Endpoint 2 IN
Endpoint 3 IN
Endpoint 4 OUT
Endpoint 5 IN
76543210
Power On Value
XXXXXXX0
Full/Empty
Reserved
76543210
Power On Value
0 0 00 0
Data Receive/Transmit
Error Code
Setup Packet
Data 0/1 Packet
Previous Status not Read
000
76543210
Power On Value