ISD91200 Series Technical Reference Manual
Release Date: Sep 16, 2019
- 400 -
Revision 2.4
16KHz
24
off
1x
64
12
on
2x
128
6
on
4x
256
4
on
6x
384
8KHz
48
off
1x
64
24
on
2x
128
12
on
4x
256
8
on
6x
384
7.3.4.4
Configuring Speaker Driver
To operate the speaker driver the following configuration is recommended:
•
Enable DPWM clock source (CLK_APBCLK0.DPWMCKEN, CLK_CLKSEL1.DPWMCKSEL).
•
Reset DPWM IP block. (SYS_IPRST1.DPWMRST)
•
Select sample rate based on current DPWM_CLK frequency.
•
Setup PDMA channel to provide data to DPWM.
•
Enable PDMA Request.
•
Enable Driver.
To operate the speaker driver the following configuration is recommended with BIQ and Volume control.
•
Enable DPWM clock source (APBCLK0.DPWMCKEN, CLKSEL1.DPWMSEL).
•
Reset DPWM IP block. (IPRST1.DPWMRST,IPRST1.BIQ_RST).
•
Enable BIQ clock source (APBCLK0.BIQALCEN).
•
Enable BIQ on DPWM path (BIQ_CTL.PATHSEL, BIQ_CTL.BIQEN,
BIQ_CTL.DPWMPUSR, BIQ_CTL.STAGE, BIQ_CTL.HPFON).
•
Set BIQ coefficient(BIQ_COEFF)
•
Setup DPWM volume control (VOLCTRL_EN.DPWMVOLEN,VOLCTRL_DPWMVAL).
(note: setup BIQ_CTL.DLCOEFF =1 and BIQ enable BIQ_CTL.BIQEN =1 for BIQ operation).
•
Select sample rate based on current DPWM_CLK frequency and set ZOHDIV
•
Setup PDMA channel to provide data to DPWM.
•
Enable PDMA Request.
•
Enable DPWM IP (DPWM_CTL.DPWMEN).
7.3.4.5
Peripheral DMA Request
Normal use of the DPWM is with PDMA. In this mode DPWM requests PDMA service whenever there
is space in FIFO. PDMA channel will copy data from a streaming buffer to the DPWM and alert the CPU
when buffer is empty. In this way an entire buffer of data can be sent to DPWM without any CPU
intervention.