ETC SPCA751A-P101

Preliminary
SPCA751A-P101
Description
The SPCA751A is a single chip signal processor optimized for MPEG audio decoding and voice recording. It is
developed to achieve a better performance/cost ratio for MPEG audio players.
The SPCA751A is especially designed for standalone audio players, the system controller can easily carry out the
MPEG audio decoding process by the use of a general serial IO/control interface for MPEG bit stream in/out and
playback control.
Decoded audio PCM data are output to external DAC through a programmable normal/I2S DAC interface, such that
most of common audio DACs can be cooperated with SPCA751A to meet different customers' requirements.
A high quality 10-bit 8KHz sampling rate ADC is embedded for voice recording. Based on the algorithm of
SACM_S480 or SACM_S3200, voice is compressed to a low data rates of 4.8Kbps and 32Kbps respectively, while
retaining a good resolution of the original speech/audio.
The SPCA751A is designed for 3.3V applications, A built in PLL is able to synthesize the system clock from a
16.934MHz crystal oscillator source. The high performance SPCA751A signal processor can operate at 34MHz and
dissipate low power, which makes the SPCA751A extremely suitable for portable systems.
A common implementation utilizing the SPCA751A is presented below:
LCD
Key Scan
PC parallel or
USB port
FM / AM Tuner
Normal / I 2S
SPCA751A
DRAM
ATAPI (CDROM/HD)
Audio DAC
(8KHz 10bit)
System uP
(SPCP751A)
FLASH/Plug-in
Cards
3.3V
DSA / I 2C
DC-DC
Converter
CDdsp interface
CD Kit
MPEG Audio Player System Block Diagram
1
Microphone
AA battery x 1
Speaker
Preliminary
SPCA751A-P101
Features
• Single chip MPEG audio decoder
• Low power dissipation
- Conforming to MPEG1/MPEG2 audio layer 2/3
- Extension to MPEG lower sampling rates
• PLL embedded
- Require only 16.934MHz crystal, resistors, and
capacitors to supply the system clock
• Digital sound control
- Digital volume control
- Stereo/Mono channel select
- Digital sound equalizer
• Built-in Digital Recording option
- Embedded 10-bit 8 kHz audio ADC
- SACM_S480 recording with 4.8 kbit/sec
- SACM_S3200 recording with 32 kbit/sec
• Internal auto-generate audio clock
- Sampling frequency from 8 kHz up to 48 kHz
• Device Parameter
- Supply voltage : 3.0 ~ 3.6 volts
- IO interface : 5 volts tolerance, TTL compatible
- Package : 44-pin LQFP
- Power consumption: less than 150 mW @ 3.6 volts
• Programmable audio DAC interface
- Support both normal and I2S audio DAC formats
- Audio clock polarity programmable
- Internal auto-generated oversampling clock for DAC
Accept external audio clock for sampling rate control
• Serial data IO and control interface
- Easy for the host processor to command
SPCA751A BLOCK DIAGRAM
AIP
AIN
ATO
VM
OSCOUT
OSCIN
ADC
MPEG Audio Decoder
PLL
Voice Encoder/Decoder
Clock
Synthesizer
Host Interface
PCM
Buffer
AUD_LRCK
AUD_BCK
AUD_DATA
AUD_XCK
TFS RFS SCLK DR
DT FCEB1 FCEB2
2
Preliminary
SPCA751A-P101
Function Description
The SPCA751A is a single-chip CMOS microprocessor optimized for real-time MPEG audio decoding and
speech/audio recording.
SPCA751A decodes the encoded MPEG audio data according to the commands passed through the Serial
Control/Data I/O Interface by the host processor, the host processor can also check the status of decoding process by
the use of this interface. Refer to Programming Guide for command definitions
In the digital recorder mode, speech/Audio is sampled at 8Khz by the on-chip ADC into 10-bit digital words, after
encoding, the datum is compressed into a data rate of 4.8Kbps or 32Kbps.
Decoded audio PCM data are output to external DAC through a programmable normal/I2S PCM interface, this
interface is compliant to most of the common audio DACs.
The embedded PLL is capable of providing the 27 MHz system clock derived from a 16.934MHz clock source
! Serial Control/Data I/O Interface
The host controller uses this interface to transfer MPEG bit-stream with the SPCA751A and to command the
SPCA751A during the recording/decoding process. This interface consists of seven pins:
FCEB1
FCEB2
Host
Controller
SCLK
RFS1
SPCA
751A
TFS1
DR1
DT1
"
Pin
# 12
FCEB2
Frame Decoded Indicator generated by the SPCA751A
Pin
# 13
FCEB1
Data Request Flag generated by the SPCA751A
Pin
# 44
SCLK1
Bit Clock controlled by the host processor
Pin
#
1
DT1
Data from the SPCA751A to the host processor
Pin
#
2
TFS1
Transmit Frame Synchronization controlled by the host processor
Pin
#
3
DR1
Data from the host processor to the SPCA751A
Pin
#
4
RFS1
Receive Frame Synchronization controlled by the host processor
FCEB1 - Data Request Flag
The FCEB1 flag generated by the SPCA751A informs the status of the decoding/encoding process. When FCEB1
is high, it indicates that the SPCA751A is ready to receive data/command or to transfer data, the host processor is
allowed to start the communication; When FCEB1 is low, the SPCA751A is busy processing internally and no I/O tasks
could be taken, the commands sent by the host processor during low FCEB1 are not accepted by the SPCA751A and
may cause the SPCA751A run into an unknown state.
3
Preliminary
"
SPCA751A-P101
FCEB2 - Frame Decoded Indicator
Each time the SPCA751A has decoded one frame (512 bytes) of data, it changes the state of FCEB2 (either high
to low or low to high) and progresses to the next frame. By counting the number of state-changes, the host processor
is able to know the time elapsed in decoding.
"
Host Command
The host commands consist of 8-bit command and 8-bit ID, totally 16-bit long. (Refer to the SPCA751A
Programming Guide for command definitions) At the falling edges of SCLK1, the SPCA751A checks whether the RFS1
is high. Once it is high, the 16-bit long command is sampled at the following 16 consecutive falling edges of SCLK1
with MSB first. After the LSB is sent, the host processor should send at least one more cycle of SCLK1 to the
SPCA751A.
SCLK1
TSCLK
RFS1
TFS
TDS
TDH
TFH
DR1
"
b15
b14
b1
b0
Host processor writes 512 bytes to the SPCA751A
At the falling edges of SCLK1, the SPCA751A checks whether the RFS1 is high. Once it is high, the 512-byte long
data is sampled at the following 512x8 consecutive falling edges of SCLK1. RFS1 should remain high before the MSB
of the last word. After the LSB of the last word is sent, the host processor should send at least three more cycles of
SCLK1 to the SPCA751A.
SCLK1
TSCLK
RFS1
TDS
TFS
TFH
TDH
DR1
b15
b14
b0
255 words
b0
b15
Last word
Timing Requirements
PARAMETER
TFS
TFH
TDS
TDH
TSCLK
MIN.
MAX.
UNIT
RFS1 setup before SCLK1 falls low
2
ns
RFS1 hold after SCLK1 falls low
2
ns
DR1 setup before SCLK1 falls low
3
ns
DR1 hold after SCLK1 falls low
3
ns
SCLK1 period
16
*
ns
* The maximum period of SCLK1 depends on the sampling rate of the decoded data, too long a SCLK1
period makes the real-time decoding impossible.
4
Preliminary
"
SPCA751A-P101
Host processor reads 512 bytes from the SPCA751A
To read data from the SPCA751A, the host processor first asserts the TFS1 at the falling edges of SCLK1, then the
512-byte long data is sampled out from the SPCA751A at the following 512x8 consecutive rising edges of SCLK1. The
host processor is supposed to latch-in the data at the falling edges of SCLK1. TFS1 should remain high before the
MSB of the last word. After the LSB of the last word is received, the host processor should send at least three more
cycles of SCLK1 to the SPCA751A.
SCLK1
TSCLK
RFS1
TFS
TFH
TDH
TD
DR1
b15
b14
b0
255 words
b0
b15
Last word
Timing Requirements
PARAMETER
TFS
TFH
TSCLK
MIN.
MAX.
UNIT
TFS1 setup before SCLK1 falls low
2
ns
TFS1 hold after SCLK1 falls low
2
ns
SCLK1 period
16
ns
Switching Characteristics
PARAMETER
TD
TDH
!
MIN.
DT1 access
MAX.
5
TSCLK / 2
DT1 hold after SCLK1 falls low
UNIT
ns
ns
PLL
An independent analog power is applied through pin 41 VSSP and pin 42 VDDP to supply the power for the
internal PLL. An oscillation circuit is built externally on pin 39 OSCIN and pin 40 OSCOUT.
10 M Ohm
pin 40
OSCOUT
pin 39
OSCIN
16.934MHz
Crystal
12 pF
12 pF
Oscillation Circuit
5
Preliminary
!
SPCA751A-P101
PCM Interface
The PCM Interface is used to output decoded audio data to external audio DAC. There are 4 signals, AUD_XCK,
AUD_LRCK, AUD_BCK and AUD_DATA. The signal format of PCM Interface is programmable with register 0x3fDE.
Register Name Register # Bits Description
AUD_CONFIG 0x3FDE
14
(Value set at initialization) (0x2103)
Audio out configuration (RW)
bit 0 = I2S control
bit 1 = AUD_XCK select
bit 2 = AUD_DATA LSB / MSB sent first
bit 3 = AUD_BCK active edge
bit 4 = AUD_XCK IO select
bit 5 = LRCK polarity
bit 12 = CD-DA pass through mode
(0 = I2S, 1 = normal)
(0 = 256×Fs, 1 = 384×FS)
(0 = MSB first, 1 = LSB first)
(0 = falling, 1 = rising)
(0 = output, 1 = input)
(0 = LRCK low is right, 1 = LRCK low
is left)
(0 = disable, 1 = enable)
Normal Mode:
AUD_BCK
AUD_LRCK
AUD_DATA
0 15 14
1
0 15 14
1
0 15 14
BCK = 32 x Fs
AUD_BCK
AUD_LRCK
AUD_DATA
0
15
14
1 0
15
14
1 0
15
BCK = 48 x Fs
I2S Mode:
AUD_BCK
AUD_LRCK
AUD_DATA
1 0 15 14
1
0 15 14
1
0 15
BCK = 32 x Fs
AUD_BCK
AUD_LRCK
AUD_DATA
0 1514
0
1514
BCK = 48 x Fs
PCM Interface waveform
6
0
1514
Preliminary
!
SPCA751A-P101
ADC
The SPCA751A has an audio-band sigma-delta analog-to-digital converter so as to meet the
requirement of the digital recorder application. The circuit of converter consists of two main blocks: the analogto-digital converter (ADC) and internal reference and bias voltage. For the latter, it is 15-bit format with 10-bit
resolution.
The analog-to-digital conversion chain consists of a microphone amplifier (M.A.), a programmable gain
amplifier (PGA), an analog oversampled modulator, and the decimation digital filter. The PGA has gain step
from –12dB to 12dB (-12, -6, 0, 6, 12dB). The modulator is a sigma-delta feedback loop, which oversamples the
signal at 1.024MHz and provides second-order noise shaping. It performs the conversion of the differential
analog input signal to a pulse-density-modulated single-bit digital output. When a maximum positive differential
input voltage is applied at the input of modulator, the resulting code at the output of the modulator is all ones.
The decimation digital filter consists of a comb filter and a half-band filter. The comb filter is a third-order comb
filter. Finally the encoder implements the half-band filter and data compression by software.
ADC & DAC ELECTRICAL CHARACTERISTICS (TA = 25ºC, VDD = 3.3 V)
PARAMETER
ATO:
CONDITION
MIN.
TYP.
MAX.
UNIT
0.25*VDD
Vpp
12
dB
MA gain = 0dB,
Input Voltage
PGA:
PGA gain = 6dB
Default: 6dB
Gain Range
-12
Step Size
Step Variation
6
dB
0.5
dB
Voltage Reference:
Output Voltage
0.45VDD
0.5VDD
0.55VDD
Vpp
MIN.
TYP.
MAX.
UNIT
ADC PATH CHARACTERISTICS
PARAMETER
ADC:
CONDITION
FIN = 1kHz,
Signal to noise ratio
PGA gain = 12dB
ATO is full swing
Without data compression
7
60
dB
Preliminary
SPCA751A-P101
DIGITAL RECODER APPLICATION CIRCUIT
A/D
converter
Analog
reference
voltage
generator
P.G.A.
(-12,-6,0,
6,12dB)
Microphone
Amplifier
ATO
390pF
MICVCC
AVDD1
AIN
AIP
10 F
Ω
Ω
AVSS1
Ω
Controller
IO port
Ω
VM
Ω
10 F
0.1 F
Ω
47 F
MICGND
8
0.1 F
M
Microphone
Ω
0.1 F
Preliminary
SPCA751A-P101
Pin Description
PIN No.
Mnemonic
Type Description
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
DT1
TFS1
DR1
RFS1
RESET
CLKSEL
VDD
VSS
VDDO
VSSO
N.C.
FCEB2
FCEB1
VDD
VSS
N.C.
VDDO
VSSO
VDD
VSS
N.C.
N.C.
VDDO
VSSO
AUD_XCK
AUD_DATA
AUD_BCK
AUD_LRCK
VDD
VSS
VDDA
VSSA
AIP
AIN
ATO
VM
VDDO
VSSO
OSCIN
OSCOUT
VSSP
VDDP
CLKIN
O
I/O
I
I/O
I
I
I
I
I
I
I
I
I/O
O
O
O
I
I
I
I
I
I
O
O
I
I
I
O
I
I
I
44
SCLK1
I/O
O
O
I
I
I
I
I
I
Transmit Data of Serial Port
Transmit Frame Synchronization of Serial Port
Receive Data of Serial Port
Receive Frame Synchronization of Serial Port
System Reset (Active Low)
System Clock Select (0: Internal PLL 1:External Oscillator)
Digital Power
Digital Ground
Digital Power
Digital Ground
No Connection
Frame Decoded Indicator
Data Request Flag
Digital Power
Digital Ground
No Connection
Digital Power
Digital Ground
Digital Power
Digital Ground
No Connection
No Connection
Digital Power
Digital Ground
Oversampling Clock to external Audio DAC / from external source
Serial Data Output to Stereo Audio DAC
Bit Clock Output to Stereo Audio DAC
Sample Rate Clock Output to Stereo Audio DAC
Digital Power
Digital Ground
Analog Power for Audio ADC
Analog Ground for Audio ADC
Positive Input of the Audio ADC transmit input amplifier
Negative Input of the Audio ADC transmit input amplifier
Output of the Audio ADC transmit input amplifier
1/2 AVDD for the bias of the Audio ADC transmit input amplifier
Digital Power
Digital Ground
16.934MHz Oscillator Input
16.934MHz Oscillator Output
Analog Ground for PLL
Analog Power for PLL
External System Clock
(Connect to VSS if internal PLL is used (pin 82 CLKSEL == 0))
Bit Clock of Serial Port
9
Preliminary
SPCA751A-P101
23
24
25
26
27
28
29
30
31
34
22
35
21
36
20
37
19
SPCA751A
38
39
18
17
LQFP 44
40
16
11
10
9
8
12
7
44
6
13
5
43
4
14
3
42
2
15
1
41
DT1
TFS1
DR1
RFS1
RESETB
CLKSEL
VDD
VSS
VDDO
VSSO
NC
AIN
ATO
VM
VDDO
VSSO
OSCIN
OSCOUT
VSSP
VDDP
CLKIN
SCLK1
32
33
AIP
VSSA
VDDA
VSS
VDD
AUD_LRCK
AUD_BCK
AUD_DATA
AUD_XCK
VSSO
VDDO
PIN Map
10
NC
NC
VSS
VDD
VSSO
VDDO
NC
VSS
VDD
FCEB1
FCEB2
VDD
5K
0.1F
Host
Processor
12 pF
RESET
LQFP 44
12 pF
390pF
100K
0.1F
10F
M
Microphone
47F
0.1F
10F
2.2K
1K
0.1F
2.2K
2.2K
100K
20K
DAC
Application Circuit
AUD_LRCK
AUD_BCK
AUD_DATA
AUD_XCK
AVDD
AVSS
VM
ATO
AIN
AIP
10M
16.934MHz Crystal
10K
CLKIN
SPCA751A
OSCOUT
OSCIN
SPCA751A
11
RFS1
DR1
TFS1
DT1
SCLK1
FCEB2
FCEB1
SPCA751A-P101
Preliminary
Preliminary
SPCA751A-P101
ABSOLUTE MAXIMUM RATINGS
Rating
Symbol
Value
Unit
Supply Voltage
VDD
0.0
~
Input Voltage
VIN
- 0.3
~
Operating Temperature
TA
0
~
60
ºC
-55
~
125
ºC
Storage Temperature
TSTG
3.6
V
VDD + 0.3
V
DC ELECTRICAL CHARACTERISTICS (TA = 25ºC, VDD = 3.3 V)
PARAMETER
CONDITION
VDD
Supply Voltage
VIL
Input Low Voltage
VIH
Input High Voltage
VOH
Output High Voltage
IOH = -4mA
VOL
Output Low Voltage
IOL = 4mA
IDD
Power Supply Current
MIN.
3.0V
TYP.
3.3V
MAX.
3.6V
0.2VDD
0.8VDD
2.4V
30.0mA
VDD
0.3V
0.6V
35.0mA
40.0mA
Ordering Information
"
Package type : 44 pin LQFP
Note: SUNPLUS TECHNOLOGY CO. LTD reserves the right to make changes at any time without notice in
order to improve the design and performance to supply the best possible product
12
Preliminary
SPCA751A-P101
Outline Dimensions
D
D1
D2
E E1 E2
e
b
c
A2
L1
A1
A
Symbol
Min.
Nom.
Max.
D
D1
D2
E
E1
E2
e
b
A
A1
A2
c
L1
0.22
0.05
1.35
0.09
-
12
10
8
12
10
8
0.80
0.30
1.40
1.0
0.38
1.60
0.15
1.45
0.20
-
Unit : millimeter
13