The HPC46164 and HPC46104 are members of the HPCTM family of High Performance microControllers Each member of the family has the same core CPU with a unique memory and I O configuration to suit specific applications The HPC46164 has 16k bytes of on-chip ROM The HPC46104 has no on-chip ROM and is intended for use with external memory Each part is fabricated in National's advanced microCMOS technology This process combined with an advanced architecture provides fast flexible I O control efficient data manipulation and high speed computation The HPC devices are complete microcomputers on a single chip All system timing internal logic ROM RAM and I O are provided on the chip to produce a cost effective solution for high performance applications On-chip functions such as UART up to eight 16-bit timers with 4 input capture registers vectored interrupts WATCHDOGTM logic and MICROWIRE PLUSTM provide a high level of system integration The ability to address up to 64k bytes of external memory enables the HPC to be used in powerful applications typically performed by microprocessors and expensive peripheral chips The term ``HPC46164'' is used throughout this datasheet to refer to the HPC46164 and HPC46104 devices unless otherwise specified The HPC46164 and HPC46104 have as an on-board peripheral an 8-channel 8-bit Analog-to-Digital Converter This A D converter can operate in a single-ended mode where the analog input voltage is applied across one of the eight input channels (D0D7) and AGND The A D converter can also operate in differential mode where the analog input voltage is applied across two adjacent input channels The A D converter will convert up to eight channels in singleended mode and up to four channel pairs in differential mode