Microcontrollers User manual

UM10237_2 © NXP B.V. 2008. All rights reserved.
User manual Rev. 02 — 19 December 2008 615 of 792
NXP Semiconductors
UM10237
Chapter 23: LPC24XX I
2
S interface
5.3 Transmit FIFO Register (I2STXFIFO - 0xE008 8008)
The I2STXFIFO register provides access to the transmit FIFO. The function of bits in
I2STXFIFO are shown in Table 23–534
.
5.4 Receive FIFO Register (I2SRXFIFO - 0xE008 800C)
The I2SRXFIFO register provides access to the receive FIFO. The function of bits in
I2SRXFIFO are shown in Table 23–535
.
5.5 Status Feedback Register (I2SSTATE - 0xE008 8010)
The I2SSTATE register provides status information about the I2S interface. The meaning
of bits in I2SSTATE are shown in Table 23–536
.
Table 533: Digital Audio Input register (I2SDAI - address 0xE008 8004) bit description
Bit Symbol Value Description Reset
Value
1:0 wordwidth Selects the number of bytes in data as follows: 01
00 8 bit data
01 16 bit data
10 Reserved, do not use this setting
11 32 bit data
2 mono When one, data is of monaural format. When zero, the
data is in stereo format.
0
3 stop Disables accesses on FIFOs, places the transmit
channel in mute mode.
0
4 reset Asynchronously reset the transmit channel and FIFO. 0
5 ws_sel When 0 master mode, when 1 slave mode. 1
14:6 ws_halfperiod Word select half period minus one, i.e. WS 64clk period
-> ws_halfperiod = 31.
0x1F
15 Unused Unused. 1
Table 534: Transmit FIFO register (I2STXFIFO - address 0xE008 8008) bit description
Bit Symbol Description Reset Value
31:0 I2STXFIFO 8 × 32 bits transmit FIFO. Level = 0
Table 535: Receive FIFO register (I2RXFIFO - address 0xE008 800C) bit description
Bit Symbol Description Reset Value
31:0 I2SRXFIFO 8 × 32 bits transmit FIFO. level = 0
Table 536: Status Feedback register (I2SSTATE - address 0xE008 8010) bit description
Bit Symbol Description Reset
Value
0 irq This bit reflects the presence of Receive Interrupt or Transmit Interrupt. 0
1 dmareq1 This bit reflects the presence of Receive or Transmit DMA Request 1. 0
2 dmareq2 This bit reflects the presence of Receive or Transmit DMA Request 2. 0
7:3 Unused Unused. 0