uda1321 NXP Semiconductors, uda1321 Datasheet - Page 18

• Manufacturer Part Number: uda1321
• Description: Universal Serial Bus Usb Digital-to-analog Converter Dac
• Manufacturer: NXP Semiconductors

Philips Semiconductors
Start-up and configuration of the UDA1321
S
After power-on, an internal power-on reset signal becomes
HIGH after a certain RC-time (R = 5 k and C = C
During 10 ms after power-on reset the UDA1321 has to
initiate the internal settings. After the power-on reset the
UDA1321 becomes master of the I
tries to read the eventually connected EEPROM and if an
EEPROM is detected, the internal descriptors are
overwritten and the selected port configuration is applied.
If no EEPROM is detected, the UDA1321 tries to read the
logical levels of GP3 and GP0. A choice can be made from
four configuration maps via these two pins.
C
MATRIX
The UDA1321 uses a configuration map to hold a number
of specific configurable data on hardware, product,
component and USB configuration level. At start-up
without EEPROM, the UDA1321 will scan the logical levels
of GP3 and GP0. With these two pins it is possible to
select one of the four possible (vendor specific)
configuration maps. This selection can be achieved via a
diode matrix (see Fig.6).
1998 Oct 06
handbook, full pagewidth
TART
ONFIGURATION SELECTION OF THE
Universal Serial Bus (USB)
Digital-to-Analog Converter (DAC)
-
UP OF THE
connector
USB-B
6
5
UDA1321
10 nF
1
2
3
4
10 nF
V bus
UDA1321
2
C-bus. The UDA1321
TR3
22 pF
3.3 V
1.5 k
VIA A DIODE
Fig.6 Diode matrix selection.
22 pF
3.3 V
ref
22 k
22 k
).
22
TR1
3.3 V
18
22
22 k
KEY 1
SW1
After selecting a configuration map the user cannot
change the chosen settings for the GP pins, internal
configuration, descriptors, etc.
For more information about the four (vendor specific)
configuration maps and the diode matrix see the
application documentation.
C
EEPROM
If an EEPROM is detected (reading byte 0 as AAH and
byte 1 as 55H), the UDA1321 will use the configuration
map in the EEPROM instead of one of four configuration
maps. The layout of the configuration map is fixed, the
values (except bytes 0 and 1) are user definable (see
Table 6). If the user wants to change these values
(the manufacturers name for instance), this can be
achieved via the EEPROM code.
The communication between the UDA1321 and the
external I
protocol given in the Philips specification “The I
how to use it (including specifications)” , which can be
ordered using the code 9398 393 40011. The I
two lines: a clock line SCL and a serial data line SDA
(see Fig.7).
ONFIGURATION OPTIONS OF THE
TR2
3.3 V
KEY 2
22 k
SW2
2
C-bus device is based on the standard I
22 k
22 k
1
2
D2
1
2
D1
V bus
UDA1321
Preliminary specification
22 k
MGM109
UDA1321
GP0
GP3
GP5
D
D
VIA AN
2
2
C-bus and
C-bus has
I
2
2
C-
C-bus
BUS