A 16bit ARM - (THUMB)
This was taken from the newsgroup comp.sys.acorn on 10th June 1994
I got this info from Texas Instruments commercial documentation:
==============================================================
[Intro with stuff about how good the ARM7DM 32 bit RISC technology is
I agree wholeheartedly!]
ARM Documents
ARM7DM RISC processor, rev.E, Dec.93, ARM DDI 0010E
ARM70DM RISC processor, rev.E, Dec.93, ARM DDI 0021E
ARM Software Development Toolkit:
-Reference Manual, Oct 93, ARM DUI - 0002B
-Technical Specifications, Oct 93, ARM DUI - 0003B
-User Manual, Oct 93, ARM DUI, - 0004B
-CookBook, Oct 93, ARM DUI, - 0005B
-Release Notes, Release 1.6, Oct 93
-C compiler, Assembler & Linker command summary
Bibliography:
-The ARM RISC Chip, A Programmer's Guide
Alex Van Someren and Carol Atack, Addison Wesley, ISBN 0-201-62410-9
[new page]
ARM70DT
What is the ARM70DT?
-The ARM70DT is a 32BIT RISC core Processor using a compact 16 bit
instruction set
What are the reasons for such processor?
-In Portable Systems the cost/size constrains are the leading care abouts
-The performance is now a major concern as more functions are required
from the controller
ARM70DT v ARM70DM
CODE DENSITY
65% of ARM70DM
ARM70DM ARM70DT
Test Suite 1944 Bytes 1264 Bytes
PERFORMANCE
150% of ARM70DM in a 8/16 bit environment
ARM70DM ARM70DT
8 bit 150 ns Memory 159 ms 97 ms
16 bit 150 ns " 83 ms 54 ms
8 bit 200 ns " 212 ms 129 ms
16 bit 200 ns " 110 ms 71 ms
ARM70DT ROADMAP
ARM70DT COMPILER V1.0 MAY 94
ARM70DM Pie Board To Simulate ARM70DT JULY 94
ARM70DT TOOLS V2.0 NOV 94
ARM70DTPG FEB 95
ARM70DT First Silicon Samples APRIL 95
========================================================
Sounds like ARM and Texas are entering the embedded
microcontrollers market, where external buses are generally 8/16 bit.
Thinking about it, it's a gazillion pieces per year opportunity
if ARM comes out with a powerful chip to compete with Motorola's 603xx,
68hc16, Intel 80196s and others...no DOS compat. required, yuppee :-)
This is a very smart move IMHO since 32 bit wide buses are much more
expensive and claim a larger board space, hence the ARM/Texas chips
can appeal a much larger audience.
Also, being involved in Real Time sw, I know how handy an all-conditional
instruction set would be...RT is a field where the excellent ARM
assembler would shine. But, apart from the external interface, what is
this 16bit instruction set?
How come it's faster?
Anyone@ARM.LTD care to explain?
My bet is that we will see some ARM core with HW uarts, RAM, ROM,
timers and other peripherals on chip later or (better) sooner.
It's about time to phase out my 68HC11 board at home :-)
Hopefully.
--
Maurizio
Long live Acorn
Name and Address witheld by request.
poppy@poppyfields.net