PDIUSBD Philips Semiconductors, PDIUSBD Datasheet - Page 8

• Manufacturer Part Number: PDIUSBD
• Description: USB device with serial interface
• Manufacturer: Philips Semiconductors

Philips Semiconductors
Clock Division Factor Byte
Clock Division Factor
Data Flow Commands
Data flow commands are used to manage the data transmission
between the USB endpoints and the monitor. Much of the data flow
is initiated via an interrupt to the microcontroller. The microcontroller
utilizes these commands to access and determine whether the
endpoint FIFOs have valid data.
Read Interrupt Register
Command
Data
Interrupt Register Byte 1
This command indicates the origin of an interrupt. A ‘1’ indicates an
interrupt occurred at this endpoint. The bits are cleared by reading
the endpoint status register through the Read Endpoint Status
command.
After a bus reset, an interrupt will be generated and bit 6 of the
Interrupt Register Byte 2 will be ‘1’. The interrupt is internally cleared
by reading the interrupt register. A bus reset is completely identical
to the hardware reset through the RESET_N pin with the sole
difference of interrupt notification.
1999 Jul 22
USB device with serial interface
7
X X
7
0
6
0
6
X X
5
5
0
4
: F4h
: Read 2 bytes
4
0
3
1
The value indicates clock division factor for
CLKOUT. The output frequency is
48 MHz/(N+1) where N is the Clock Division
Factor. The reset value is 11. This will
produce the output frequency of 4 MHz
which can then be programmed up (or down)
by the user. The minimum value is one giving
the range of frequency from 4 to 24 MHz.
The PDIUSBD11 design ensures no
glitching during frequency change. The
programmed value will not be changed by a
bus reset.
3
0
2
0
2
0
1
1
1
X
0
1
X
0
POWER ON VALUE
CLOCK DIVISION FACTOR
RESERVED
POWER ON VALUE
RESERVED
CONTROL OUT ENDPOINT
CONTROL IN ENDPOINT
ENDPOINT INDEX 4
ENDPOINT INDEX 5
ENDPOINT INDEX 6
ENDPOINT INDEX 7
SV00828
SV00829
8
Interrupt Register Byte 2
Select Endpoint
Command
Data
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, which returns ‘0’ if the buffer is empty and
‘1’ if the buffer is full.
Full/Empty
X X
7
7
X
6
6
0
X X
5
X X
5
: 00-0Dh
: Optional Read 1 byte
A ‘1’ indicates the buffer is full, ‘0’ indicates an
empty buffer.
4
4
3
X X
3
X X
2
2
1
X
1
0
0
0
0
0
POWER ON VALUE
ENDPOINT INDEX 8
ENDPOINT INDEX 9
RESERVED
BUS RESET
RESERVED
POWER ON VALUE
FULL/EMPTY
RESERVED
PDIUSBD11
SV00830
SV00831
Product specification