
Philips Semiconductors
PNX15xx Series
Volume 1 of 1
Chapter 16: Audio Input
PNX15XX_SER_3
Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Product data sheet
Rev. 3 — 17 March 2006
16-10
3.5 Memory Data Formats
The Audio In unit autonomously writes samples to memory in mono and stereo 16
and 32-bit per sample formats, as shown in
Figure 6. Successive samples are always
stored at increasing memory address locations.
3.5.1
Endian Control
The following table illustrates exactly how the Audio Inout block writes data in
memory (byte) locations precisely after the correct endian swapping done at the
adapter depending on the polarity of the big-endian bit in the Global Registers
Module.
Figure 6:
Audio In Memory DMA Formats
Table 5: Operating Modes and Memory Formats
NR_CHAN MODE
Source of Successive Samples
00
mono (one channel)
SD0.left
00
stereo (one channel)
SD0.left, SD0.right
01
mono (two channels)
SD0.left, SD1.left
01
stereo (two channels)
SD0.left, SD0.right, SD1.left, SD1.right
10
mono (three channels)
SD0.left, SD1.left, SD2.left
10
stereo (three channels)
SD0.left, SD0.right, SD1.left, SD1.right, SD2.left, SD2.right
11
mono (four channels)
SD0.left, SD1.left, SD2.left, SD3.left
11
stereo (four channels)
SD0.left, SD0.right, SD1.left, SD1.right, SD2.left, SD2.right, SD3.left, SD3.right.
16 bit, stereo,
NR_CHAN=00
16 bit, stereo,
NR_CHAN=10
32 bit, stereo,
NR_CHAN=00
adr
SD0.leftn
adr
SD0.leftn
adr
SD0.leftn
adr+2
SD0.right n
adr+2
SD0.right n
adr+4
SD0.leftn+1
adr+4
SD1.leftn
adr+4
SD0.right n
adr+6
SD0.right n+1
adr+6
SD1.right n
adr+8
SD0.leftn+2
adr+8
SD2.leftn
adr+10
SD0.right n+2
adr+10
SD2.rightn
adr+8
SD0.leftn+1
adr+12
adr+14
SD0.leftn+3 SD0.rightn+3
adr+12
adr+14
SD0.leftn+1 SD0.rightn+1
adr+12
SD0.rightn+1
32 bit, stereo,
NR_CHAN=10
SD0.leftn
SD0.right n
SD1.leftn
SD1.right n
SD2.leftn
SD2.right n
SD0.leftn+1 SD0.rightn+1
adr
adr+4
adr+8
adr+12
adr+16
adr+20
adr+24
adr+28
32 bit, mono,
NR_CHAN=00
adr
SD0.leftn
adr+4
SD0.left n+1
adr+8
SD0.leftn+2
adr+12
SD0.leftn+2
Table 6: Endian Ordering of Audio Data in Main Memory
Operating
Modes
m[adr]
m[adr+1]
m[adr+2]
m[adr+3]
m[adr+4]
m[adr+5]
m[adr+6]
m[adr+7]
16-bit mono -
little endian
leftn[7:0]
leftn[15:8]
leftn+1[7:0]
leftn+1[15:8
]
leftn+2[7:0]
leftn+2[15:8]
leftn+3[7:0]
leftn+3[15:8]
16-bit mono -
big endian
leftn[15:8]
leftn[7:0]
leftn+1[15:8
]
leftn+1[7:0] leftn+2[15:8] leftn+2[7:0]
leftn+3[15:8]
leftn+3[7:0]
16-bit stereo
- little endian
leftn[7:0]
leftn[15:8]
rightn[7:0]
rightn[15:8] leftn+1[7:0]
leftn+1[15:8]
rightn+1[7:0]
rightn+1[15:8
]