AR1688 chip is designed especially for lowcost and singlechip IP phone.

Integrated MCU, the instruction set is compatible with Z80
MCU run at 24.576MHz(typical), F/W can program from DC up to 60MHz
Internal 116 Kbytes RAM, no external SDRAM needed for most application
Up to 4 chip selection for external SRAM, EEPROM or FLASH, each can support 2MB at maximum
24 bits DSP Core
2181-instruction-set compatible DSP co-processor
DSP Speed up to 72MIPS
Support 24.576MHz OSC with on-chip PLL for DSP
Up to 16 general purpose I/O pins
High quality 18bits CODEC on chip.
One UART port
Support real time clock
Keypad support (up to 12 keys directly)
Maximum voice output: 11mW@16 ohm
Internal DC/DC converter to produce CORE voltage, eliminate external LDO
Operating Voltage: IO: 3.3v, Core: 1.8v
Low Power consumption: <90mW at typical
LQFP-100(14x14mm) package

If you have a mind to buy the lowcost and singlechip IP phone with AR1688 chip, please contact following companies:

http://www.high-link.cn

http://www.digitmat.com
http://www.digitmat.com.cn

More information: http://www.palmmicro.com.cn
AR1688 and PA1688 based IP phone mailing list — http://groups.yahoo.com/group/pa1688
VOIP and AR1688 BLOG — http://aredfox.spaces.live.com