IEEE802.11a Based Wireless AV Module(WAVM) with Digital AV Interface. Outline

Size: px

Start display at page:

Download "IEEE802.11a Based Wireless AV Module(WAVM) with Digital AV Interface. Outline"

Wesley Warren
6 years ago
Views:

1 IEEE802.11a Based Wireless AV Module() with Digital AV Interface TOSHIBA Corp. T.Wakutsu, N.Shibuya, E.Kamagata, T.Matsumoto, Y.Nagahori, T.Sakamoto, Y.Unekawa, K.Tagami, M.Serizawa Outline Background Key techniques Timing jitter removal function for MPEG2 TS data IR command path-through IIC I/F function Status consistency control Block diagram Experiment results Conclusions

2 Background Enhancement of IEEE standard is continuing. b, g, a, e, h, i, n and so on WLAN became very popular for PC applications. Wireless feature is attractive for non-pc applications. VoWLAN Wireless Audio/Video(AV) transfer PC peripheral WLAN equipments are not directly applicable to the non-pc applications. AV application requires the AV specific capability. (Wireless Audio / Video Module) Specific LSI equipped with AV I/Fs has been developed. Proprietary protocol is defined for the AV data transmission because the standardization is not finalized yet. Target Application Terrestrial/Satellite television Wireless TV application Control commands Station a Audio / Video IR commands Monitor Requirements Robust data and low latency transmission. Jitter removal caused by WLAN. IR command pass-through function. Status consistency control between s. IR remote controller

3 Key Techniques of Jitter removal function for MPEG2 data. IR remote control signal pass-through. IIC bus interface. Status consistency control. Module partitioning. architecture. Jitter Removal Function Input MPEG Data Time WLAN The timing jitter at the WLAN output is inevitable. Causes of timing jitter Transmission retry of WLAN. The queue management of the MAC(Medium Access Control). Bit rate control according to the radio quality. The MPEG2 TS decoder requires that the variation of delay time should be suppressed within 500nsec.

4 Jitter Removal Function(Cont d) <Transmitter side> MPEG2 TS Data 27MHz Add Timestamp Counter value Internal counter WLAN MAC parameters are optimized. The received data is stored so as to absorb the timing jitter. WLAN Internal counter Counter value compare Time stamp Buffer <Receiver side> 27MHz MPEG2 TS Data The MPEG data is output when the time stamp value equals to the internal counter value. Synchronization Because of the frequency offset between the transmitter and the receiver, the synchronization function is needed. The acceleration / deceleration control is performed by controlling the counter value, according to the total amount of the stored MPEG2 packets. MPEG2 TS Data Received MPEG2 Packet Counter value compare Time stamp Buffer Acceleration Threshold Deceleration Increment the counter value Internal counter Decrement the counter value 27MHz

5 IR Remote Control Signal Pass-through Broadcast Television AM-modulated remote control signal Non AM-modulated remote control signal Monitor (LCD, PDP) DVD Player IR system cable VCR Tuner Station Over-sampling data of the IR command signal. Audio / Video IR commands IR remote controller IR reception module Any IR remote controller can be used. Example of IR Signal Waveform G-code transmission (TOSHIBA VCR remote controller) Monitor side IR original signal Packetized 64msec Received packet This signal is over-sampled continuously and packetized. WLAN Time Regenerated signal Station side IR signal waveform is reproduced at the station side.

6 IIC Bus Interface IIC Bus I/F 1 control - status read -Command write Station System CPU has two types of IIC bus I/Fs which are designed to be appropriate for each purpose. IIC Bus I/F 2 Dedicated data path between station / monitor system CPUs Monitor System CPU Video LSI IIC I/F1 IIC I/F2 Radio Link IIC IIC I/F2 I/F1 Video LSI IIC Bus I/F 2 The IIC bus I/F2 is designed so as to fit the packet data transmission. IIC I/F 2 IIC Bus Select FIFO Buffer FIFO Buffer Select From/To WLAN BB LSI IIC I/F 2 Controller Interrupt By using IIC bus I/F2, the transmission efficiency is improved. Large capacity data transmission is possible. The packet size is defined by the register of the IIC I/F1.

7 Status Consistency Control Station CPU IIC bus I/F Radio Monitor CPU IR Controller IIC bus I/F IR Recognition of TV ch. change request. => Tuner control Status Information (such as TV_Ch=1) Ack TV_Ch.= 1 6 Status Information (such as TV_Ch=6) Ack IR command of TV ch. change request (set to TV ch.=6) Recognition of TV ch. change request. => OSD (On Screen Display) update (TV ch. = 6) Even though the command packet is lost, the status of the monitor is synchronized to the status of the station because the status information is periodically transmitted. MPEG Rate Setting (Automatic-mode) (5) TC35672 sets MPEG encoding rate. Station Tuner Video Dec. System CPU MPEG Enc (6) Message of rate change complete. IIC I/F 1 Register TC35672 always shows the status by the register. (3) Adaptive control based on radio quality starts. IR controller System CPU Register TC35672 IIC I/F 1 (1) User selects the mode by OSD menu. (2) CPU sets the automatic-mode (by the command) MPEG Dec Monitor Display Scaler (4) Rate change request message

8 Key Techniques of Jitter removal function for MPEG2 data. IR remote control signal pass-through. IIC bus interface. Status consistency control. Module partitioning. architecture. Module Partitioning The appropriate I/Fs are selected to apply a wireless function into the existing TV set. SDRAM MPEG LSI AV I/F LSI WLAN BB LSI WLAN RF FROM IIC IR IR Emission AV Source Selector Video Dec. Audio ADC 656 PCM OSD Processing Sound Processing Display ROM/RAM CPU IR monitor IR Reception Interrupt, Mode setting Video Enc. Audio DAC

9 Block Diagram Video ITU-R BT.656 Audio PCM Audio (IIS Available) IIC Bus IR Remote Control MPEG2 TS SDRAM (MPEG2 Codec LSI) TC6405 (AV Specified I/F LSI) Control PA TB32152 (RF IC) TA32151 (IF IC) TC35672 (BB LSI) TX39 CPU RF Out SW Flash ROM AV specific digital I/Fs AV specific functions Embedded CPU controls all the function of Block Diagram of AV I/F LSI MPEG Block Buffer TC6405 Timing Control MPEG2 TS Rx I/F MPEG2 TS Tx I/F Time Stamp Add. System Control Unit AM IIC I/F1 IIC I/F2 IR I/F PIO PCIC

10 Block Diagram of WLAN BB LSI CPU Block Tx39 CPU (80MHz) Program (2Mbit) Frame (2Mbit) TC PCIC CG (PLL) G-Bus (40MHz) 32 ROMC Tx-PHY IRC MAC Ctrl-MAC Tx-MAC Rx-MAC DAC PHY Rx-PHY ADC Radio I/F Radio Control DMA (4ch.) Bridge Serial EEPROM TMR IM-Bus SIO FLASH Chip Features WLAN LSI(TC35672) Process 0.18um CMOS 6layer metal (Random: 1.27Mgates, : 4.29Mbits) Chip Size 10.9 x 10.9 mm Package 361pin PFBGA(Plastic Fine pitch Ball Grid Array) Supply Voltage Core: 1.5V, Analog: 2.5V, I/O: 3.3V Frequency 20/40/80MHz AV I/F LSI(TC6405) Process 0.18um CMOS 5layer (Random: 251Kgates, : 1.63Mbits) Chip Size 7.1 x 7.1 mm Package 217pin PFBGA (0.8mm pitch) Supply Voltage Core: 1.5V, I/O: 3.3V Frequency 27/33MHz

11 70mm WLAN BB LSI Photograph Program 32bit CPU (Tx39) PLL Frame 10bit DAC x2 10bit ADC x2 Ripple cancellation comparator I/O 7bit DAC x2 Photograph Radio Board BB LSI

12 Features Wireless audio/video transmission Timing jitter removal to satisfy MPEG2-TS delay spread WLAN parameters are optimized for AV data transmission. Using clear 5GHz band WLAN (suitable to the home application) Packet by packet selection antenna diversity. High performance super heterodyne radio architecture. Easy-add-on to an existing TV system. All-in-one module including an MPEG2 encoder/decoder LSI Embedded CPU in BB LSI controls all the function of. No additional CPU is used in. AV I/F LSI equipped with the AV specific function and I/Fs. Status consistency control. Small size 70 x 100 x 11 mm Air-transmission Examples Measurement Condition (closed meeting room) Room A Room B Room C 7m Station Monitor Through four steel boards Results Tx power is reduced for severe condition (set to 0dBm). Radio PHY Rate 24 Mbps 12 Mbps 6 Mbps MPEG Encoding Rate 14.4 Mbps 6.0 Mbps 2.7 Mbps Normal condition Severe condition Even the 24Mbps result under severe condition, the result may be improved if antenna arrangement is optimized.

Conclusions achieved all the necessary features for home AV application. Simplest wireless function extension into the conventional TV set. All-in-One module including an MPEG2 Encoder/Decoder LSI.

13 Conclusions achieved all the necessary features for home AV application. Simplest wireless function extension into the conventional TV set. All-in-One module including an MPEG2 Encoder/Decoder LSI. Provides AV specific function. Rapid wake up. Short latency control (Ex. tuner ch. change time). Future plan Digital HD (High Definition) stream transmission with secure content protection. AV transmission protocol standardization. Pier5 LSI Logic

Advanced System LSIs for Home 3D Systems

ASP-DAC2011 Session 8D-1 Advanced System LSIs for Home 3D Systems January 28, 2011 Takao Suzuki Panasonic Corporation Strategic Semiconductor Development Center Agenda 1. Overview of 3D Systems - Principles