80C186EB/80C188EB Microprocessor User's Manual - CEUNES

CHIP-SELECT UNIT;SET UP CHIP SELECTS; UCS# - EPROM Select; LCS# - SRAM Select; GCS1# - DRAM Select; GCS2# - FLOPPY Select; GCS0# - DMA SelectMOV DX, UCSSP ;Finish setting up UCS#MOV AX, UCSSP_VALOUT DX, AL ;Remember, byte writes work okMOV DX, LCSST ;Set up LCS#MOV AX, LCSST_VALOUT DX, ALMOV DX, LCSSPMOV AX, LCSSP_VALOUT DX, AL ;Remember, byte writes work okMOV DX, GCS1ST ;Set up GCS1#MOV AX, GCS1ST_VALOUT DX, ALMOV AX, GCS1SP_VALMOV DX, GCS1SPOUT DX, AL ;Remember, byte writes work okMOV DX, GCS0ST ;Set up GCS0#MOV AX, GCS0ST_VALOUT DX, ALMOV AX, GCS0SP_VALMOV DX, GCS0SPOUT DX, AL ;Remember, byte writes work okMOV DX, GCS2ST ;Set up GCS2#MOV AX, GCS2ST_VALOUT DX, ALMOV DX, GCS2SPMOV AX, GCS2SP_VALOUT DX, AL ;Remember, byte writes work ok;Place remaining User Code here.CODEENDS;POWER ON RESET CODE TO GET STARTEDASSUME CS:POWER_ONPOWER_ONSEGMENT AT 0FFFFHMOV DX, UCSST ;Point to UCS registerMOV AX, UCSST_VAL ;Reprogram UCS# for EPROM sizeOUT DX, ALJMP FW_START ;Jump to start of init codePOWER_ON ENDSExample 6-1. Initializing the Chip-Select Unit (Continued)6-19