MCIMX281AVM4B Freescale Semiconductor, MCIMX281AVM4B Datasheet - Page 2204

• Manufacturer Part Number: MCIMX281AVM4B
• Description: IC MPU I.MX28 1.2 289MAPBGA
• Manufacturer: Freescale Semiconductor
• Series: i.MX28r

Specifications of MCIMX281AVM4B

• Core Processor: ARM9
• Core Size: 32-Bit
• Speed: 454MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, MMC, SmartCard, SPI, SSI, UART/USART, USB OTG
• Peripherals: DMA, I²S, LCD, POR, PWM, WDT
• Program Memory Size: 128KB (32K x 32)
• Program Memory Type: Mask ROM
• Ram Size: 32K x 32
• Voltage - Supply (vcc/vdd): 1.25 V ~ 5.25 V
• Data Converters: A/D 17x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 289-LFBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of I /o: -
• Eeprom Size: -
• Lead Free Status / Rohs Status: Supplier Unconfirmed

Operation
Because there is a small amount of error in the sample rates generated by the fractional
divider, software needs to periodically alter the HW_CLKCTRL_SAIF_DIV value higher
or lower, depending on the difference between the required and actual sample rates. For an
audio-only playback application, this adjustment need not ever be performed, because the
frequency phase shift is imperceptible. However, it is needed for applications such as locking
to and playing from an FM tuner, or audio/video applications where AV synchronization
is required. For an audio/video application, it is typically accepted that audio and video
cannot diverge any greater than ± 20 ms.
elapsed time between each DIV adjustment required to keep within this 20-ms limit. Note
that the smallest elapsed time is just under 20 seconds. Typically, software can be configured
to periodically monitor the read and write pointers for the digital PCM audio buffer in
OCRAM or SDRAM. When the pointers either become close to overrunning each other or
close to the 20-ms AV divergence point, the DIV value should be increased or decreased
incrementally (LSBs).
Table 35-1. HW_CLKCTRL_SAIF_DIV Values for Standard Sample Rates/Oversample Base
2204
192000
176200
128000
Sample
96000
88100
64000
Rate
(Hz)
Multiplier
sample
Over-
Base
Rate
512
384
512
384
512
384
512
384
512
384
512
384
90.2144
67.6608
45.1072
33.8304
saif_clk
98.304
73.728
65.536
49.152
49.152
36.864
32.768
24.576
quired
(MHz)
Re-
i.MX28 Applications Processor Reference Manual, Rev. 1, 2010
0.2048000000
0.1536000000
0.1879466667
0.1409600000
0.1365333333
0.1024000000
0.1024000000
0.0768000000
0.0939733333
0.0704800000
0.0682666667
0.0512000000
Fractional
Desired
Divisor
0.2048034668
0.1535949707
0.1879425049
0.1409606934
0.1365356445
0.1024017334
0.1024017334
0.0767974854
0.0939788818
0.0704803467
0.0682678223
0.0511932373
Fractional
Closest
Divisor
Actual
Table 35-1
Rates
0011010001101110
0010011101010010
0011000000011101
0010010000010110
0010001011110100
0001101000110111
0001101000110111
0001001110101001
0001100000001111
0001001000001011
0001000101111010
0000110100011011
DIV Binary Value
contains a column that lists the average
0x301D
0x0D1B
0x346E
0x22F4
0x1A37
0x1A38
0x13A9
0x180F
0x120B
0x117A
0x2752
0x2416
Value
Hex
DIV
Freescale Semiconductor, Inc.
132.1
(ppm)
Error
16.9
32.7
22.1
16.9
16.9
16.9
32.7
59.0
16.9
4.9
4.9
< Actual
DIV Adjustment
347.3
610.8
903.2
193.5
210.9
151.4
151.4
610.8
193.5
151.4
(Notes
94.5
96.8
DIV
Frequency
(seconds)
1
> Actual
and
1181.5
4066.0
1181.5
1181.5
1181.5
4066.0
1181.5
300.3
338.8
120.5
338.8
120.5
DIV
2
)