Memory Configuration - HP FRAM71B User Manual

FRAM71B
9 Memory Configuration
The total memory space in FRAM71B is 16 x 32 KB = 512 KByte, where 32 KByte in F_Block 2
is unused, because it overlaps with HP-71B RAM (except for the configuration area). Hence,
the total usable FRAM space is 480 KByte, organized in 15 F_Blocks:
FRAM Address
F_Block # Start
0 0x00000
0x10000
1
*)
2 0x20000
*)
2 0x2C000
*)
2 0x2C020
3 0x30000
4 0x40000
0x50000
5
6 0x60000
7 0x70000
8 0x80000
9 0x90000
A 0xA0000
B 0xB0000
C 0xC0000
D 0xD0000
E 0xE0000
F 0xF0000
Table 1: FRAM71B F_Block- and Configuration- Locations in BOT FRAM.
*) No Chip must be assigned to F_Block 2
F_Blocks are presented to the HP-71B in the form of memory-"Chips" that may represent a
memory module on their own, or may be clustered into larger memory modules. Chips do
not have pre-defined addresses in FRAM, but get assigned to user-selected F_Blocks. Chip
configuration data is stored in FRAM, and will survive a power loss or a "MEMORY LOST".
v F_Block 2 must not be used for Chip-assignments.
Configuration of Chips and Memory Modules is accomplished by [POKE] commands at the
Card Reader's address space C_0x2C000 – C_0x2C01F.
Each byte-value in that address space configures
· The size of a Chip,
· Whether it is part of a module that contains multiple Chips,
· Whether its device type is RAM or soft configured ROM,
· Which F_Block it is assigned to.
The position of a configuration byte inside the 16-byte-long configuration string corresponds
to its respective Chip, see FRAM71B configuration example on next page:
FRAM71B 1.00
End
0xFFFFF
0x1FFFF
0x2BFFF
0x2C01F
0x2FFFF
0x3FFFF
0x4FFFF
0x5FFFF
0x6FFFF
0x7FFFF
0x8FFFF
0x9FFFF
0xAFFFF
0xBFFFF
0xCFFFF
0xDFFFF
0xEFFFF
0xFFFFF
- 12 -
Purpose
HC = Hard Configured
SC = Soft Configured
SYSRAM / RAM / ROM
SYSRAM / RAM / ROM
unused
Config Area For FRAM allocation
Unused
RAM / ROM
RAM / ROM
RAM / ROM
RAM / ROM
RAM / ROM
RAM / ROM
RAM / ROM
RAM / ROM
RAM / ROM
RAM / ROM
RAM / ROM
RAM / ROM
RAM / ROM
User's Manual
©Hans Brueggemann, 2016