/* Imported from Wayback Machine
   Original URL : https://retrobrewcomputers.org/doku.php?id=builderpages:plasmo:cb030:cb030_rev1:cb030r1_memmap
   Snapshot date: 2025-02-14
   Generator    : wayback-archiver
*/

====== CB030 Rev 1 Memory Map ======

The memory map of CB030 (rev1) at reset is as follow:

EPROM from 0x0 to 0xFEFF_FFFF, the EPROM is 512K (0x0-0x7FFFF), the memory is aliased every 512K up to 0xFEFF_FFFF.

I/O resources is at 0xFF00_0000 to 0xFFFF_FFFF

68681 address is 0xFFFF_F000-0xFFFF_FFFF

Compact flash interface is 0xFFFF_E000-0xFFFF_EFFF

RC2014-like expansion slot is from 0xFFFF_C000-0xFFFF_CFFF for I/O addresses (nIORQ signal asserted), 0xFFFF_D000 to 0xFFFF_DFFF for memory addresses (nMREQ signal asserted).

Remap register is 0xFFFF_8000-0xFFFF_8FFF, any access (read or write) to 0xFFFF_8000 will cause EPROM to reside in 0xFE00_0000 to 0xFEFF_FFFF

(rev1.2 version of CPLD) 100Hz level 2 autovector interrupt turned on by accessing 0xFFFF_9800. Turn off the 100Hz timer by accessing 0xFFFF_9000

Once the remap register is access, the memory map is changed to:

RAM from 0x0 to 0x7FF_FFFF. If the DRAM is single bank 16 meg DRAM, it is located at 0x0-0x100_0000 and aliased three time to 0x3FF_FFFF. If the DRAM is 64 meg, then it is located at 0x0-0x3FF_FFFF. If the DRAM is 128meg it is located from 0x0-0x7FF_FFFF.

EPROM from 0xFE00_0000 to 0xFEFF_FFFF, the EPROM is 512K, the memory is aliased every 512K up to 0xFEFF_FFFF.

I/O from 0xFFFF_0000 to top of memory

68681 address is 0xFFFF_F000-0xFFFF_FFFF

Compact flash interface is 0xFFFF_E000-0xFFFF_EFFF

RC2014-like expansion slot is from 0xFFFF_C000-0xFFFF_CFFF for I/O addresses (nIORQ signal asserted), 0xFFFF_D000 to 0xFFFF_DFFF for memory addresses (nMREQ signal asserted).

Remap register is 0xFFFF_8000-0xFFFF_8FFF, any access (read or write) to 0xFFFF_8000 will cause EPROM to reside in 0xFE00_0000 to 0xFEFF_FFFF.

EQU template for 68681

<code code>
DUART    equ $FFFFF000    * base address of 68692 DUART
MRA    equ $FFFFF000    * mode reg A
SRA    equ $FFFFF002    * status A (read)
CSRA    equ $FFFFF002    * clock select reg (write)
CRA    equ $FFFFF004    * command register (write only)
RHRA    equ $FFFFF006    * Rx Hold reg A (read)
THRA    equ $FFFFF006    * Tx Holding reg (write)
IPCR    equ $FFFFF008    * Input port change reg (read)
ACR    equ $FFFFF008    * Aux control reg (write)
ISRD    equ $FFFFF00A    * interrupt status reg (read)
IMRD    equ $FFFFF00A    * interrupt mask reg (write)
CTU    equ $FFFFF00C    * Counter/timer upper (read)
CTL    equ $FFFFF00E    * counter/timer lower (read)
CTUR    equ $FFFFF00C    * Counter/timer preload upper (write)
CTLR    equ $FFFFF00E    * counter/timer preload lower (write)
MR1B    equ $FFFFF010    * mode reg B
SRB    equ $FFFFF012    * status reg B
RHRB    equ $FFFFF016    * Rx holding reg B
IVRD    equ $FFFFF018    * interrupt vector reg
STOPCTR    equ $FFFFF01E    * stop counter command reg (read)
STARTCTR equ $FFFFF01C    * start counter command reg (read)
SETOPR    equ $FFFFF01C    * bit set output register bits (write)
CLROPR    equ $FFFFF01E    * bit clear output register (write)
OPCR    equ $FFFFF01A    * output configuration register(write)
</code>

EQU template for CF interface

<code code>
CFdata  equ $FFFFE000       * CF data register
CFerr   equ $FFFFE001       * CF error reg
CFsectcnt equ $FFFFE002      * CF sector count reg
CF07    equ $FFFFE003       * CF LA0-7
CF815   equ $FFFFE004       * CF LA8-15
CF1623  equ $FFFFE005       * CF LA16-23
CF2427  equ $FFFFE006       * CF LA24-27
CFstat  equ $FFFFE007       * CF status/command reg
</code>