tea5761uk NXP Semiconductors, tea5761uk Datasheet - Page 10

• Manufacturer Part Number: tea5761uk
• Description: Tea5761uk Low-voltage Single Chip Fm-stereo Radio
• Manufacturer: NXP Semiconductors

Philips Semiconductors
9397 750 13451
Product data sheet
8.20.1 Search mode
8.17 Standby mode
8.18 Power-on reset
8.19 I
8.20 Auto search and Preset mode
The radio can be put into Standby mode by Power-Up / Power-Down bit PUPD. In this
mode, the FM part can be turned off. The TEA5761UK is still accessible via the I
but takes only very low power from the supply. In Standby mode, the audio outputs are
hard muted.
When the supply voltages V
and outputs, the audio outputs and the reference clock input are in high-impedance state.
The power supplies can be switched on in any order.
After start-up of V
the registers will be set to their default values. The power-on reset is effectively generated
by V
At power-on reset, the mute is set and all other bits are set to the reset value as given in
Table
The I
When, during operation, the signal on pin BUSENABLE is toggled, the device will not
generate an I
necessary to send either the I
or send the complete I
restored in the normal behavior. Now an I
transmitted byte again.
In Search mode the IC can search channels automatically; see
When the INTX signal is used as an interrupt to the microcontroller to indicate a search
stop, the INTMSK register must be reset and only bit FRRMSK must be set. In this way
the microcontroller will only be interrupted when the search or preset algorithm is ready.
Search mode is initiated by setting bit SM in byte FRQSETMSB to logic 1. The search
direction is set by bit SUD; bit SUD = 0 (search down), bit SUD = 1 (search up). The tuner
starts searching at the frequency from where it is or at a start frequency set in bytes
FRQSETLSB and FRQSETMSB. The Search Stop Level (SSL) bits define the field
strength level at which a desired channel is detected. The tuner will stop on a channel with
a field strength equal to or higher than this reference level and then checks the IF
frequency; when both are valid, the search stops. If the level check or the IF count fails,
the search continues. If no channels are found, the TEA5761UK stops searching when it
has reached the band limit, setting bit BLFLAG HIGH. A search always stops when the
FRRFLAG is set and on the occurrence of a hardware interrupt, this procedure is shown in
Figure
2
C-bus interface
CCD
2
9. To initialize the TEA5761UK all bytes have to be transferred.
C-bus interface operates with a maximum clock frequency of 400 kHz.
3.
.
2
C-bus acknowledge bit on the first following I
CCA
and V
2
Rev. 01 — 2 August 2006
C-bus transmission twice. After this, the I
CCA
CCD
2
C-bus address two times prior to the complete transmission
and V
a power-on reset circuit will generate a reset pulse and
CCD
2
are made 0 V and VREFDIG = HIGH, all inputs
C-bus acknowledge is generated on each
Low voltage single-chip FM stereo radio
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
2
C-bus transmission. It is then
Figure
TEA5761UK
2
C-bus communication is
3.
2
C-bus
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