Software specifications TDA7566
22/29 Doc ID 9801 Rev 6
If R/W = 1, the TDA7566 sends 4 "Diagnostics Bytes" to mP: DB1, DB2, DB3 and DB4.
Table 7. IB2
Bit Instruction decoding bit
D7 0
D6 0
D5 0
D4
Standby on - Amplifier not working - (D4 = 0)
Standby off - Amplifier working - (D4 = 1)
D3
Power amplifier mode diagnostic (D3 = 0)
Line driver mode diagnostic (D3 = 1)
D2
Current detection diagnostic enabled (D2 = 1)
Current detection diagnostic defeat (D2 = 0)
D1 0
D0 0
Table 8. DB1
Bit Instruction decoding bit
D7 Thermal warning active (D7 = 1)
D6
Diag. cycle not activated or not terminated (D6 = 0)
Diag. cycle terminated (D6 = 1)
D5
Channel LF
Current detection
Output peak current < 250mA - Open load (D5 = 1)
Output peak current > 500mA - Open load (D5 = 0)
D4
Channel LF
Turn-on diagnostic (D4 = 0)
Permanent diagnostic (D4 = 1)
D3
Channel LF
Normal load (D3 = 0)
Short load (D3 = 1)
D2
Channel LF
Turn-on diag.: No open load (D2 = 0)
Open load detection (D2 = 1)
Offset diag.: No output offset (D2 = 0)
Output offset detection (D2 = 1)
D1
Channel LF
No short to Vcc (D1 = 0)
Short to Vcc (D1 = 1)
D0
Channel LF
No short to GND (D1 = 0)
Short to GND (D1 = 1)
