SLASF36A January 2024 – December 2024 TAC5311-Q1
PRODUCTION DATA
In addition to supporting analog microphones, the TAC5311-Q1 also interfaces to digital pulse-density-modulation (PDM) microphones and uses high-order and high-performance decimation filters to generate pulse code modulation (PCM) output data that can be transmitted on the audio serial interface to the host. The device supports up to four digital microphone recording channels (when the analog channels are not used). The device can also support simultaneous recording on one analog and three digital microphone channels.
The GPIO1, GPIxA and GPO1A pins can be configured for the PDM data lines (PDMDINx) and PDM Clock (PDMCLK) functions as per the Table 6-57 for the digital PDM microphone recording.
The device internally generates PDMCLK with a programmable frequency of either 6.144MHz, 3.072MHz, 1.536MHz, or 768kHz (for output data sample rates in multiples or submultiples of 48kHz) or 5.6448MHz, 2.8224MHz, 1.4112MHz, or 705.6kHz (for output data sample rates in multiples or submultiples of 44.1kHz) using the PDM_CLK_CFG[1:0] (P0_R53_D[7:6]) register bits. PDMCLK can be routed on the GPIO1 and GPO1A pins using the respective configuration registers: GPIO1_CFG (P0_R10[7:4]) and GPO1A_CFG (P0_R12[7:4]). This clock can be connected to the external digital microphone device. Figure 6-19 shows a connection diagram of the digital PDM microphones.
The single-bit output of the external digital microphone device can be connected to the GPIxA or GPIO1 pin. The device supports two PDM data lines: PDMDIN1 and PDMDIN2 set through the registers PDM_DIN1_SEL (P0_R19_D[3:2]) and PDM_DIN2_SEL (P0_R19_D[1:0]). When using GPIxA, make sure that the GPI function is enabled using the GPI_CFG (P0_R13[1]). This single data line can be shared by two digital microphones to place their data on the opposite edge of PDMCLK. Internally, the device latches the steady value of the data on either the rising or falling edge of PDMCLK based on the configuration register bits set in PDMDIN1_EDGE (P0_R19_D[4]) and PDMDIN2_EDGE (P0_R19_D[5]). Figure 6-20shows the digital PDM microphone interface timing diagram.
When the digital microphone is used for recording, the analog blocks of the respective ADC channel are powered down and bypassed for power efficiency. Channel 3 and channel 4 support only the digital microphone interface. Use the PDM_CH1_SEL[1:0] (P0_R19_D[7]) and PDM_CH2_SEL[1:0] (P0_R19_D[6]) register bits to select the analog microphone or digital microphone for channel 1 to channel 2 respectively.