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VMM ATOMIC GENERATOR
VMM has two types of generators. Atomic generator and Scenario generator.
Atomic generator is a simple generator which generates transactions randomly.
`vmm_atomic_gen is a macro which is used to define a class named <class_name>_atomic_gen for any user-specified class derived from vmm_data, using a process similar to the `vmm_channel macro.
To use <class_name>_atomic_gen class, a <class_name>_channel must exist. <class_name>_atomic_gen generates transactions and pushes it to <class_name>_channel. A <class_name>_channel object can be passed to generator while constructing.
function new(string instance,
int stream_id = -1,
<class_name>_channel out_chan = null);
The generator will stop generating the transaction after generating stop_after_n_insts. User can set the stop_after_n_insts to any unsigned int value. By default this values is 0.
If stop_after_n_insts is 0, then generator generates infinite number of transactions.
If stop_after_n_insts is non zero positive number, then generator generates stop_after_n_insts transactions.
We will see an example of creating a atomic generator for a packet class. Packet class is in file Packet.sv .
1) define `vmm_atomic_gen macro for packet class. This macro creates a packet_atomic_gen class creates and randomizes packet transactions.
`vmm_atomic_gen(packet,"packet atomic generator")
2) define `vmm_channel for the packet class. This macro creates a packet_channel which will be used by the packet_atomic_gen to store the transactions. Any other component can take the transactions from this channel.
`vmm_channel(packet)
3) Create an object of pcakt_atomic_gen.
packet_atomic_gen pkt_gen = new("Atomic Gen","test");
4) Set the number of transactions to be generated to 4
pkt_gen.stop_after_n_insts = 4;
5) Start the generator to generate transactions. These transactions are available to access through pkt_chan as soon as they are generated.
pkt_gen.start_xator();
6) Collect the packets from the pkt_chan and display the packet content to terminal.
pkt_gen.out_chan.get(pkt);
pkt.display();
Completed Example
`vmm_channel(Packet)
`vmm_atomic_gen(Packet,"Atomic Packet Generator")
program test_atomic_gen();
Packet_atomic_gen pkt_gen = new("Atomic Gen","test");
Packet pkt;
initial
begin
pkt_gen.stop_after_n_insts = 4;
#100; pkt_gen.start_xactor();
end
initial
#200 forever
begin
pkt_gen.out_chan.get(pkt);
pkt.display();
end
endprogram
Download the example
vmm_atomic_gen.tar
Browse the code in vmm_atomic_gen.tar
Commands to run the simulation
vcs -sverilog -f filelist -R -ntb_opts rvm -ntb_opts dtm
Log file report
packet #1952805748.0.0
da:0xdb
sa:0x71
length:0x0e (data.size=1)
data[0]:0x63
fcs:0xe9
packet #1952805748.0.1
da:0xa7
sa:0x45
length:0xa4 (data.size=5)
data[0]:0x00 data[1]:0x4f .... data[3]:0xe7 data[4]:0xd8
fcs:0x31
packet #1952805748.0.2
da:0x15
sa:0xe6
length:0xa1 (data.size=1)
data[0]:0x80
fcs:0x01
packet #1952805748.0.3
da:0xd7
sa:0xa9
length:0xdc (data.size=3)
data[0]:0xcc data[1]:0x7c data[1]:0x7c
fcs:0x67
VMM has two types of generators. Atomic generator and Scenario generator.
Atomic generator is a simple generator which generates transactions randomly.
`vmm_atomic_gen is a macro which is used to define a class named <class_name>_atomic_gen for any user-specified class derived from vmm_data, using a process similar to the `vmm_channel macro.
To use <class_name>_atomic_gen class, a <class_name>_channel must exist. <class_name>_atomic_gen generates transactions and pushes it to <class_name>_channel. A <class_name>_channel object can be passed to generator while constructing.
function new(string instance,
int stream_id = -1,
<class_name>_channel out_chan = null);
The generator will stop generating the transaction after generating stop_after_n_insts. User can set the stop_after_n_insts to any unsigned int value. By default this values is 0.
If stop_after_n_insts is 0, then generator generates infinite number of transactions. If stop_after_n_insts is non zero positive number, then generator generates stop_after_n_insts transactions.We will see an example of creating a atomic generator for a packet class. Packet class is in file Packet.sv .
1) define `vmm_atomic_gen macro for packet class. This macro creates a packet_atomic_gen class creates and randomizes packet transactions.
`vmm_atomic_gen(packet,"packet atomic generator")
2) define `vmm_channel for the packet class. This macro creates a packet_channel which will be used by the packet_atomic_gen to store the transactions. Any other component can take the transactions from this channel.
`vmm_channel(packet)
3) Create an object of pcakt_atomic_gen.
packet_atomic_gen pkt_gen = new("Atomic Gen","test");
4) Set the number of transactions to be generated to 4
pkt_gen.stop_after_n_insts = 4;
5) Start the generator to generate transactions. These transactions are available to access through pkt_chan as soon as they are generated.
pkt_gen.start_xator();
6) Collect the packets from the pkt_chan and display the packet content to terminal.
pkt_gen.out_chan.get(pkt);
pkt.display();
Completed Example
`vmm_channel(Packet)
`vmm_atomic_gen(Packet,"Atomic Packet Generator")
program test_atomic_gen();
Packet_atomic_gen pkt_gen = new("Atomic Gen","test");
Packet pkt;
initial
begin
pkt_gen.stop_after_n_insts = 4;
#100; pkt_gen.start_xactor();
end
initial
#200 forever
begin
pkt_gen.out_chan.get(pkt);
pkt.display();
end
endprogram
Download the example
vmm_atomic_gen.tar
Browse the code in vmm_atomic_gen.tar
Commands to run the simulation
vcs -sverilog -f filelist -R -ntb_opts rvm -ntb_opts dtm
Log file report
packet #1952805748.0.0
da:0xdb
sa:0x71
length:0x0e (data.size=1)
data[0]:0x63
fcs:0xe9
packet #1952805748.0.1
da:0xa7
sa:0x45
length:0xa4 (data.size=5)
data[0]:0x00 data[1]:0x4f .... data[3]:0xe7 data[4]:0xd8
fcs:0x31
packet #1952805748.0.2
da:0x15
sa:0xe6
length:0xa1 (data.size=1)
data[0]:0x80
fcs:0x01
packet #1952805748.0.3
da:0xd7
sa:0xa9
length:0xdc (data.size=3)
data[0]:0xcc data[1]:0x7c data[1]:0x7c
fcs:0x67
Index
Introduction
Vmm Log
Vmm Env
Vmm Data
Vmm Channel
Vmm Atomic Generator
Vmm Xactor
Vmm Callback
Vmm Test
Vmm Channel Record And Playback
Vmm Scenario Generator
Vmm Opts
Report a Bug or Comment on This section - Your input is what keeps Testbench.in improving with time!
Introduction
Vmm Log
Vmm Env
Vmm Data
Vmm Channel
Vmm Atomic Generator
Vmm Xactor
Vmm Callback
Vmm Test
Vmm Channel Record And Playback
Vmm Scenario Generator
Vmm Opts
Report a Bug or Comment on This section - Your input is what keeps Testbench.in improving with time!