Forth 10 times slower than C?
- From: Frank Buss <fb@xxxxxxxxxxxxx>
- Date: Sat, 14 Apr 2007 12:49:06 +0200
I've tried to use Forth on a LPC2148 microcontroller, with this nice board:
http://www.sparkfun.com/commerce/product_info.php?products_id=676
First I've tested it with an evaluation version of CrossStudio in C with
this program:
typedef unsigned char ui8;
#define FIO1DIR3 (*((volatile ui8 *) 0x3FFFC023))
#define FIO1MASK3 (*((volatile ui8 *) 0x3FFFC033))
#define FIO1SET3 (*((volatile ui8 *) 0x3FFFC03B))
#define FIO1CLR3 (*((volatile ui8 *) 0x3FFFC03F))
#define SCS (*((volatile ui8 *) 0xE01FC1A0))
void initPorts()
{
SCS = 3;
FIO1DIR3 = 1;
FIO1MASK3 = 0;
}
void ledOn()
{
FIO1SET3 = 1;
}
void ledOff()
{
FIO1CLR3 = 1;
}
void blink()
{
while (1) {
ledOn();
ledOff();
}
}
int main (void)
{
initPorts();
blink();
return 0;
}
The LED is blinking with about 2.4 MHz. Then I've downloaded and flashed
this Forth implementation:
http://www.mpeforth.com/arena.htm#lpcforth
and tested it with the same program in Forth:
\ Fast I/O setup
$3FFFC000 constant FIO_BASE_ADDR
FIO_BASE_ADDR $20 + constant FIO1DIR
FIO_BASE_ADDR $30 + constant FIO1MASK
FIO_BASE_ADDR $38 + constant FIO1SET
FIO_BASE_ADDR $3C + constant FIO1CLR
\ System Control Block(SCB)
$E01FC000 constant SCB_BASE_ADDR
\ System Controls and Status
SCB_BASE_ADDR $1A0 + constant SCS
: init-ports
3 SCS c! \ enable fast IO
1 FIO1DIR 3 + c! \ set LED pin output
0 FIO1MASK 3 + c! \ set mask
;
\ enable LED
: led-on 1 FIO1SET 3 + c! ;
\ disable LED
: led-off 1 FIO1CLR 3 + c! ;
\ very fast blink
: blink
begin
led-on
led-off
again ;
\ test
init-ports
blink
But the LED is blinking with about 275 kHz, only.
I know, it is a bit unfair, because the C compiler has the full power of a
PC for optimizing the code and the Forth system uses only less than 64 kB
for the whole system, including compiler on the target hardware, which is
really nice, but what can I expect from a Forth cross compiler? Are there
faster ANS Forth systems or cross compilers for the ARM7TDMI-S CPU
available, which are easy to use with the LPC2148 microcontroller?
--
Frank Buss, fb@xxxxxxxxxxxxx
http://www.frank-buss.de, http://www.it4-systems.de
.
- Follow-Ups:
- Re: Forth 10 times slower than C?
- From: Stephen Pelc
- Re: Forth 10 times slower than C?
- From: Charlie Springer
- Re: Forth 10 times slower than C?
- From: werty
- Re: Forth 10 times slower than C?
- From: J Thomas
- Re: Forth 10 times slower than C?
- Prev by Date: Re: Forth Frustrations
- Next by Date: Re: Rewriting and predictions
- Previous by thread: can ficl run under linux ?
- Next by thread: Re: Forth 10 times slower than C?
- Index(es):
Relevant Pages
|
Loading
