tea5767hn NXP Semiconductors, tea5767hn Datasheet - Page 13

• Manufacturer Part Number: tea5767hn
• Description: Low-power Fm Stereo Radio For Handheld Applications
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TEA5767HN_5
Product data sheet
8.3.2 Power-on reset
8.4 Writing data
A positive edge at pin WRITE/READ enables the data transfer into the IC. The data has to
be stable at the positive edge of the clock. Data may change while the clock is LOW and is
written into the IC on the positive edge of the clock. Data transfer can be stopped after the
transmission of new tuning information with the first two bytes or after each following byte.
A negative edge at pin WRITE/READ enables the data transfer from the IC. The
WRITE/READ pin changes while the clock is LOW. With the negative edge at
pin WRITE/READ the MSB of the first byte occurs at pin DATA.
The bits are shifted on the negative clock edge to pin DATA and can be read on the
positive edge.
To do two consecutive read or write actions, pin WRITE/READ has to be toggled for at
least one clock period. When a search tuning request is sent, the IC autonomously starts
searching the FM band; the search direction and search stop level can be selected. When
a station with a field strength equal to or greater than the stop level is found, the tuning
system stops and the ready flag bit is set to HIGH. When, during search, a band limit is
reached, the tuning system stops at the band limit and the band limit flag bit is set to
HIGH. The ready flag is also set to HIGH in this case.
The software programmable output (SWPORT1) can be programmed to operate as a
tuning indicator output. As long as the IC has not completed a tuning action,
pin SWPORT1 remains LOW. The pin becomes HIGH, when a preset or search tuning is
completed or when a band limit is reached.
The reference frequency divider of the synthesizer PLL is changed when the MSB in
byte 5 is set to logic 1. The tuning system can then be clocked via pin XTAL2 at 6.5 MHz.
At Power-on reset the mute is set, all other bits are random. To initialize the IC all bytes
have to be transferred.
Fig 7. 3-wire bus write data
WRITE_READ
CLOCK
DATA
t
W(write)
Rev. 05 — 26 January 2007
50 %
t
su(clk)
Low-power FM stereo radio for handheld applications
50 %
50 %
t
su(write)
50 %
valid data
t
h(write)
TEA5767HN
© NXP B.V. 2007. All rights reserved.
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