Using the simulator interface the simulated program can control the
simulation, it can get information about the interface, stop simulation
and it can do console and file io.
Interface is available behind a memory location, which can be any data memory location which is readable and writable by the program. Program can send command to the interface by writing one character command code into the memory location (although some of them needs parameter) and can read back answer from the same location.
The interface must be turned on before use. It means that you must specify the address of the memory location to use. It can be done in two ways.
Using -I option of the simulator program
-I option accepts a list of settings in form: setting=value. Know settings are:
ucsim_51 -I if=xram[0xffff]
memory name must be followed by the address in square brackets.
Address can be specified in decimal, octal or hexadecimal.Configuring virtual simif peripheral
If you check hardware elements of simulated processor with conf command, you will see one called simif. Setting of this peripheral will setup the simulator interface:
0> conf
ucsim version 0.6-pre56
Type of microcontroller: C52 CMOS cmos
Controller has 12 hardware element(s).
on simif[0]
on vcd[0]
on timer0[0]
on timer1[1]
on uart[0]
on dport[0]
on port[0]
on port[1]
on port[2]
on port[3]
on irq[0]
on timer2[2]
0>
Using info command you can get state of the interface, known commands, and other information:
0> info hw simif
uCsim simulator interface, version 1, at (null)[0x0]
Active command: none.
Known commands:
0x5f/_ if_detect: Detect existence of interface
0x69/i commands: Get information about known commands
0x76/v if_ver: Get version of simulator interface
0x56/V sim_ver: Get version of simulator
0x40/@ if_reset: Reset interface to default state
0x49/I cmdinfo: Get information about a command
0x68/h cmdhelp: Get help about a command
0x73/s stop: Stop simulation
0x70/p print: Print character
0x78/x print_hex: Print character in hex
0x66/f fin_check: Check input file if input available
0x72/r read input file: Read character from input file
0x77/w write to output file: Write character to output file
Input file:
Output file:
...
Use set hardware command to setup the interface:
0> set hw simif
set hardware simif memory address
set hardware simif fin "input_file_name"
set hardware simif fout "output_file_name"
0>
To turn on the interface, use following command:
0> set hw simif xram 0xffff 0> i h simif uCsim simulator interface, version 1, at xram[0xffff]
...
following commands can be used to specify input and output files:
0> set hw simif fin "infile.txt" 0> set hw simif fout "outfile.txt" 0> i h simif ... Input file: infile.txt Output file: outfile.txt ...
Access interface from simulated program
To access memory content, you have to use C variable. If address is already known, you can setup a pointer with that address to access the content:
#define SIF_ADDRESS_SPACE_NAME "xram" #define SIF_ADDRESS_SPACE __xdata #define SIF_ADDRESS 0xffff volatile unsigned char SIF_ADDRESS_SPACE * sif;
void main(void) { sif= (unsigned char SIF_ADDRESS_SPACE *) SIF_ADDRESS; ...
this example can be compiled with SDCC for MSC51 processor. Do not forget the volatile keyword! You can define names for command characters:
enum sif_command { DETECT_SIGN = '!', // answer to detect command SIFCM_DETECT = '_', // command used to detect the interface SIFCM_COMMANDS = 'i', // get info about commands SIFCM_IFVER = 'v', // interface version SIFCM_SIMVER = 'V', // simulator version SIFCM_IFRESET = '@', // reset the interface SIFCM_CMDINFO = 'I', // info about a command SIFCM_CMDHELP = 'h', // help about a command SIFCM_STOP = 's', // stop simulation SIFCM_PRINT = 'p', // print character SIFCM_FIN_CHECK = 'f', // check input file for input SIFCM_READ = 'r', // read from input file SIFCM_WRITE = 'w', // write to output file };
Command: detect
Command character: _
Answer: !
Following function can be used to detect if the interface is turned on or not:
char detect(void) { *sif= SIFCM_DETECT; return *sif == DETECT_SIGN; }
Command: commands
Command character: i
Answer: nuof_commands, command_char_1, command_char_2, ...
This command can be used to retrieve all know command characters. First answer is the number of known commands, further reads will get command characters. Following example will read all commands:
int nuof_commands; unsigned char commands[100]; void get_commands(void) { int i; *sif= SIFCM_COMMANDS; nuof_commands= *sif; for (i= 0; i < nuof_commands; i++) commands[i]= *sif; }
Command: ifver
Command character: v
Answer: 1 byte version number
Following simple example is a function which returns the interface version:
int get_ifversion(void) { *sif= SIFCM_IFVER; return(*sif); }
Command: simver
Command character: V
Answer: string
First byte of the string answer will be the length of the string, and after the last character a zero byte will arrive. Following function can be used to read string answer and store it (up to some limited length):
unsigned char sim_version[15]; void get_sim_version() { unsigned char c, i, n; *sif= SIFCM_SIMVER; sim_version[0]= 0; n= *sif; if (n) { i= 0; c= *sif; while (c && (i<14)) { sim_version[i++]= c; c= *sif; } while (c) c= *sif; sim_version[i]= 0; } }
Command: ifreset
Command character: @
Answer: -
This command resets the interface to default state.
Command: cmdinfo
Command character: I followed by a command character (which you would
like to get info about)
Answer: array
enum sif_answer_type { SIFAT_UNKNOWN = 0x00, // we don't know... SIFAT_BYTE = 0x01, // just a byte SIFAT_ARRAY = 0x02, // array of some bytes SIFAT_STRING = 0x03, // a string SIFAT_NONE = 0x04 // no answer at all }; void print_cmd_infos(void) { int i, j; unsigned char inf[5]; for (i= 0; i < nuof_commands; i++) { printf("Command '%c' info:\n", commands[i]); *sif= SIFCM_CMDINFO; *sif= commands[i]; inf[0]= *sif; for (j= 0; j < inf[0]; j++) { inf[j+1]= *sif; //printf(" 0x%02x", inf[j+1]); } printf(" need %d params, answers as ", inf[1]); switch (inf[2]) { case SIFAT_UNKNOWN : printf("unknown"); break; case SIFAT_BYTE : printf("byte"); break; case SIFAT_ARRAY : printf("array"); break; case SIFAT_STRING : printf("string"); break; case SIFAT_NONE : printf("none"); break; } printf(": "); *sif= SIFCM_CMDHELP; *sif= commands[i]; if (*sif) { j= *sif; while (j) { putchar(j); j= *sif; } } printf("\n"); } }
void sif_putchar(char c) { *sif= SIFCM_PRINT; *sif= c; } void sif_print(char *s) { while (*s) sif_putchar(*s++); }
char sif_fin_avail() { return sif_get(SIFCM_FIN_CHECK); }
void fin_demo() { char i, c; printf("Reading input from SIMIF input file:\n"); while (i= sif_fin_avail()) { c= sif_read(); if (c > 31) putchar(c); } printf("\nRead demo finished\n"); }
void fout_demo(char *s) { while (*s) { *sif= SIFCM_WRITE; *sif= *s++; } }Do not forget to specify name of the output file via setting of the simulator interface. Be careful, simulator will overwrite content of the output file!