Аудио-концентратор: список регистров

  Unused

  FRXN

Write 1 to flush RX FIFO, self clear to '0'.

  Unused

  RXNTL

RX FIFO Empty Trigger Level
Interrupt and DMA request trigger level for RXFIFO normal condition
Trigger Level = RXnTL

  Unused

  RXNOM

RX FIFO Output Mode(Mode 0, 1,2,3)
00: Expanding '0' at LSB of RX FIFO register
01: Expanding received sample sign bit at MSB of RX FIFO register.
10: Truncating received samples at high half-word of RX FIFO register and low half-word of RX FIFO register is filled by '0'.
11: Truncating received samples at low half-word of RX FIFO register and high half-word of RX FIFO register is expanded by its sign bit. Example for 20-bit received audio sample:
Mode 0: APB_RDATA[31:0] = {FIFO_O[31:12], 12'h0}.
Mode 1: APB_RDATA[31:0] = {12{FIFO_O[31]}, FIFO_O[31:12]}.
Mode 2: APB_RDATA[31:0] = {FIFO_O[31:16], 16'h0}.
Mode 3: APB_RDATA[31:0] = {16{FIFO_O[31]}, FIFO_O[31:16]}.

Команда U-Boot для чтения регистра

Bit fields structure

typedef union  apbif_rxnfifo_ctrl
{
  struct
  {
   unsigned rxnom : 2;
   unsigned unused0 : 2;
   unsigned rxntl : 7;
   unsigned unused1 : 1;
   unsigned frxn : 1;
   unsigned unused2 : 19;
  } b;
   unsigned long w;
} APBIF_RXnFIFO_CTRL