Register Quick Reference—IP2022 User’s Manual 386 www.ubicom.com Table C-1  Register Addresses and Reset State Address Name Description Reset
Value 0x001 Reserved Reserved Reserved 0x002 ADDRSEL Selector for current external/pro-
gram memory pointer 00000000 0x003 ADDRX External/program memory pointer
(bits 23:16) 00000000 0x004 IPH Indirect Pointer (high byte) 00000000 0x005 IPL Indirect Pointer (low byte) 00000000 0x006 SPH Stack Pointer (high byte) 00000000 0x007 SPL Stack Pointer (low byte) 00000000 0x008 PCH Current PC bits 15:8 (read-only) 11111111 0x009 PCL Virtual register for direct PC modifi-
cation 11110000 0x00A W W register 00000000 0x00B STATUS STATUS register On POR or
RST Reset:    11100000
OnBrown-out
Reset:    11101000
On WDT
Overflow: 11110000 0x00C DPH Data Pointer (high byte) 00000000 0x00D DPL Data Pointer (low byte) 00000000 0x00E SPDREG Current speed (read-only) 10010011