TEA5757 Philips Semiconductors (Acquired by NXP), TEA5757 Datasheet - Page 8

• Manufacturer Part Number: TEA5757
• Description: TEA5757; TEA5759; Self Tuned Radio (STR)
• Manufacturer: Philips Semiconductors (Acquired by NXP)

Philips Semiconductors
Description of the bus
The TEA5757; TEA5759 radio has a bus which consists of
three wires, as shown in Table 1.
Table 1 Bus signals
These three signals, together with the mono/stereo pin
(MO/ST; pin 24), communicate with the microcontroller.
The mono/stereo indicator has two functions, which are
controlled by the BUS-CLOCK, as shown in Table 2.
Table 3 Explanation of the shift register bits
Note
1. The output pins 30 and 31 can drive currents up to 5 mA; bits P0.19 and P1.18 control the output voltage of the
1999 Aug 26
BUS-CLOCK
DATA
WRITE-ENABLE write/read input
S.24 (MSB)
D.23
M.22
B0.21
B1.20
P0.19
P1.18
S0.17
S1.16
15
F.14 to F.0 (LSB) frequency
Self Tuned Radio (STR)
control pins P0 (pin 30) and P1 (pin 31):
a) Bit P0.19 LOW sets P0 (pin 30) to LOW.
b) Bit P0.19 HIGH sets P0 (pin 30) to HIGH.
c) Bit P1.18 LOW sets P1 (pin 31) to LOW.
d) Bit P1.18 HIGH sets P1 (pin 31) to HIGH.
SIGNAL
BIT
software driven clock input
data input/output
search start/end
search up/down
mono/stereo
band
port
search-level of station
dummy
DESCRIPTION
DESCRIPTION
0
1
0
1
0
1
see Table 4 selects FM/MW/LW/SW band
note 1
see Table 5 determines the locking field strength during an
PIN
LOGIC
STATE
27
28
29
8
Table 2 Bus-clock functions
The TEA5757; TEA5759 has a 25-bit shift register;
see Table 3 for an explanation of the shift register bits.
If in search mode no transmitter can be found, all
frequency bits of the shift register are set to logic 0.
The bus protocol is depicted in Figs 3 and 4.
LOW
LOW
HIGH
HIGH
after a search when a station is found or after a preset
during the search action
indicates if the radio has to search down
indicates if the radio has to search up
stereo is allowed
mono is required (radio switched to forced mono)
user programmable bits which e.g. can be used as band
switch driver
automatic search, automatic store or manual search
buffer
determine the tuning frequency of the radio; see Table 6
for the bit values
BUS-CLOCK
LOW
HIGH
LOW
HIGH
MO/ST (PIN 24)
RESULT
TEA5757; TEA5759
Product specification
stereo
mono
tuned
not tuned
RESULT