12-04-2025, 08:07 AM
(This post was last modified: 12-04-2025, 03:14 PM by WhiteHexagon.)
Can someone help me with an overview of the steps I'd need to play a PCM sample from RAM via the PinePhone speaker please? I want my bare-metal OS to have some beeps 
This is what I have so far:
LINEOUT to Speaker goes via component U800, audio amplifier, and link expired in the component list. but seems to have an interesting connection to NAND. (PA-SHDN)
[edit: ignore this paragraph, I got AC_PR working!] AC_PR Configuration Register mentioned (p362), but not sure of it's register address or usage, it mentions PRCM but doesnt explain how. It seems I'll need this for access to : 0x05 LINEOUT Control Register, and maybe to un-mute the MIX channels. [Edit: I found more information in the A80 manual it looks like R_PRCM is at 0x01F01400 in the A64,but still not clear where this AC+PR register is located.]
Looking at the data path diagram (page 280). It looks like I should be able to send PCM over I2S, but sounds like there is a mode that reads direct from RAM?
As you can hear, I'm a bit lost down the rabbit hole at the moment!
This is what I have so far:
LINEOUT to Speaker goes via component U800, audio amplifier, and link expired in the component list. but seems to have an interesting connection to NAND. (PA-SHDN)
[edit: ignore this paragraph, I got AC_PR working!] AC_PR Configuration Register mentioned (p362), but not sure of it's register address or usage, it mentions PRCM but doesnt explain how. It seems I'll need this for access to : 0x05 LINEOUT Control Register, and maybe to un-mute the MIX channels. [Edit: I found more information in the A80 manual
it looks like R_PRCM is at 0x01F01400 in the A64,but still not clear where this AC+PR register is located.]Looking at the data path diagram (page 280). It looks like I should be able to send PCM over I2S, but sounds like there is a mode that reads direct from RAM?
As you can hear, I'm a bit lost down the rabbit hole at the moment!
