1.1 Interface Description

The following figure illustrates the pin diagram of the BM20 module.

Figure 1-3. BM20 Module Pin Diagram

The following table provides the pin description of the BM20 module.

Table 1-1. BM20 Module Pin Description
Pin No.NamePin typeDescription
1P0_0I/O

I/O pin, default pull-high input (Note 1)

  • Slide switch detector, active-low
  • UART TX_IND, active-low
2EANI

Embedded ROM/External Flash enable

H: Embedded; L: External Flash

3P3_0I

I/O pin, default pull-high input (Note 1)

Line-in Detector (default), active-low

4P2_0I

I/O pin, default pull-high input

System Configuration,

H: Application L: Base band (Test Mode)

5P1_5I/O

I/O pin, default pull-high input (Note 1)

  • NFC detection pin, active low
  • Out_Ind_0
  • Slide Switch Detector, active low
  • Buzzer Signal Output
6P0_4I/O

I/O pin, default pull-high input (Note 1)

  • NFC detection pin, active low
  • Out_Ind_0
7SPKRORight-channel, analog headphone output
8AOHPMOHeadphone common mode output/sense input
9SPKLOLeft-channel, analog headphone output
10VDDAPPositive power supply/reference voltage for Codec, no need to add power to this pin
11MIC1_PIMIC 1 mono differential analog positive input
12MIC1_NIMIC 1 mono differential analog negative input
13MIC_BIASPElectric microphone biasing voltage
14AIRIRight-channel, single-ended analog input
15AILILeft-channel, single-ended analog input
16RSTISystem Reset pin, Low: reset
17VCC_RFP1.28V RF LDO output, no need to add power to this pin
18P0_1I/O

I/O pin, default pull-high input (Note 1)

  • FWD key, when Class 2 RF (default), active-low
  • Class 1 TX Control signal of external RF T/R switch, active-high
19VDD_IOPPower output, no need to add power to this pin
20ADAP_INP5V Power adapter input
21BAT_INP3.0V to 4.2V Li-Ion battery input
22NC—No connection
23GNDPGround pin
24SYS_PWRP

System power output

BAT mode: 3.0 to 4.2V

Adapter mode: 4.0V

25BK_OUTP1.8V Buck output, no need to add power to this pin
26MFBI
  • Power key in off mode
  • UART_RX_IND: MCU used to wake-up Bluetooth® (Note 1)
27LED1ILED driver 1
28LED2ILED driver 2
29P2_4I

I/O pin, default pull-high input

System Configuration

L: Boot Mode with P2_0 low combination

30P0_2I

I/O pin, default pull-high input (Note 1)

Play/Pause key (default), active-low

31P0_3I/O

I/O pin, default pull-high input (Note 1)

  • REV key (default), active low
  • Buzzer Signal Output
  • Out_Ind_1
  • Class 1 RX control signal of external RF T/R switch, active-high
32HCI_TXDOHCI-UART data output
33HCI_RXDIHCI-UART data input
34P0_5I

I/O pin, default pull-high input (Note 1)

Volume down (default), active-low

35P2_7I

I/O pin, default pull-high input (Note 1)

Volume up key (default), active-low

36P2_4I

I/O pin, default pull-high input

System Configuration,

L: Boot Mode with P2_0 low combination

37GNDPGround pin
38NC—No Connection
39NC—No Connection
40NC—No Connection
  • I: Input pin
  • O: Output pin
  • I/O: Input/Output pin
  • P: Power pin
Note: All I/O pins can be configured using the IS20XXS_UI tool.

The following figure illustrates the pin diagram of the BM23 module.

Figure 1-4. BM23 Module Pin Diagram
Table 1-2. BM23 Pin Description
Pin No.NamePin TypeDescription
1P0_0I/O
  • I/O pin, default pull-high input (Note 1)
  • UART TX_IND
2RFS0I/OI2S interface: DAC Left/Right clock
3TFS0I/OI2S interface: ADC Left/Right clock
4SLK0I/OI2S interface: Bit clock
5DR0II2S interface: DAC Digital Left/Right data
6DT0OI2S interface: ADC Digital Left/Right data
7P0_4I/OI/O pin, default pull-high input
8EANI

Embedded ROM/External Flash enable

High: ROM mode;

Low: External Flash mode

9MIC1_PIMIC 1 mono differential analog positive input
10MIC1_NIMIC 1 mono differential analog negative input
11MIC_BIASPPower output, microphone biasing voltage
12VDDAPPower output, reserve for external capacitance to fine tune audio frequency
13AIRIRight-channel, stereo analog line-in
14AILILeft-channel, stereo analog line-in
15GNDPGround
16RSTISystem Reset pin, active when rising edge
17NC——
18NC——
19VDDIOPPower output, VDDIO pin, no need to add power to this pin
20P1_5I/OI/O pin, default pull-high input
21P0_1I/OI/O pin, default pull-high input
22ADAP_INP5V power adapter input
23BAT_INP3.3V to 4.2V Li-Ion battery input
24NC——
25SYS_PWRP

System Power Output

BAT mode: 3.3 to 4.2V

Adapter mode: 4.0V

26BK_OUTP1.8V power output, no need to add power to this pin
27MFBP
  • Power key, when in Off mode
  • UART_RX_IND: MCU used to wake up Bluetooth®
28LED1PLED driver 1 and maximum 4 mA
29LED2PLED driver 2 and maximum 4 mA
30P2_4I

I/O pin, default pull-high input

System Configuration,

L– Boot Mode with P2_0 low combination

31P0_2I/OI/O pin, default pull-high input
32P0_3I/OI/O pin, default pull-high input
33HCI_TXDOHCI-UART data output
34HCI_RXDIHCI-UART data input
35P0_5I/OI/O pin, default pull-high input
36P2_7I/OI/O pin, default pull-high input
37P2_0I/OI/O pin, default pull-high input
38P3_0I/OI/O pin, default pull-high input
39P2_0I

I/O pin, default pull-high input

System Configuration,

H: Application L: Base band (Test Mode)

40GNDPGround
41NC——
42NC——
43NC——
  • I: Input pin
  • O: Output pin
  • I/O: Input/Output pin
  • P: Power pin
Note: All I/O pins can be configured using the IS20XXS_UI tool.