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module blk2 (out);
connect cmos3 cmos4 resolveto cmos3;
NetB
cmos2
cmos1 NetA
module blk1 (out);
module top;

 

Accellera

Analog and Mixed-signal Extensions to Verilog HDL

Version 2.3.1, June 1, 2009

The example in Figure 7-5 shows several effects of coercion on auto-insertion.

NetD

module digital_blk (out);

 

 

module mix

(out);

module twoblks (out);

 

 

 

 

 

NetC

cmos3

cmos2

module blk3 (out);

module blk2 (out);

cmos4

electrical

module blk4 (out);

module ablk (out);

// discrete resolveto’s ignored connect cmos1 cmos2 cmos3 resolveto cmos1; // discrete resolveto’s ignored

Figure 7-5: Coercion effects on autoinsertion

Case1: NetB is declared as cmos3 (the others are undeclared)

cmos3 top.digital_blk.twoblks.NetB

discipline resolution basic: Same as without coercion.

discipline resolution detail: NetB stays cmos3; NetA, NetC, and NetD become electrical.

Case2: NetA is declared as cmos1 (the others are undeclared)

discipline resolution basic: NetA stays cmos1, NetB is assigned cmos3, and NetC and NetD become electrical.

discipline resolution detail: Same as basic mode.

Case3: NetC is declared as cmos2 (the others are undeclared)

discipline resolution basic: NetC stays cmos2, NetB is assigned cmos3, NetA is assigned cmos1, and NetD is assigned cmos1.

discipline resolution detail: Same as basic mode.

7.5 Connect modules

Connect modules are automatically inserted to connect the continuous and discrete disciplines (mixed nets) of the design hierarchy together. The continuous and discrete disciplines of the ports of the connect modules and their directions are used to determine the circumstances in which the module can be automatically inserted.

The connect module is a special form of a module; its definition is shown in Syntax 7-4.

module_declaration ::=

// from A.1.2

161

Copyright © 2009 Accellera Organization, Inc. All rights reserved.

Accellera

 

Version 2.3.1, June 1, 2009

VERILOG-AMS

{ attribute_instance } module_keyword module_identifier [ module_parameter_port_list ] list_of_ports ; { module_item }

endmodule

| { attribute_instance } module_keyword module_identifier [ module_parameter_port_list ] [ list_of_port_declarations ] ; { non_port_module_item }

endmodule

module_keyword ::= module | macromodule | connectmodule

Syntax 7-4—Syntax for connect modules

7.6 Connect module descriptions

The disciplines of mixed nets are determined prior to the connect module insertion phase of elaboration. Connect module declarations with matching port discipline declarations and directions are instantiated to connect the continuous and discrete domains of the mixed net.

The port disciplines define the default type of disciplines which shall be bridged by the connect module. The directional qualifiers of the discrete port determine the default scenarios where the module can be instantiated. The following combinations of directional qualifiers are supported for the continuous and discrete disciplines of a connect module:

Table 7-2—Connect module directional qualifier combinations

continuous

discrete

 

 

input

output

 

 

output

input

 

 

inout

inout

 

 

Example 1:

connectmodule d2a (in, out); input in;

output out; ddiscrete in; electrical out;

// insert connect module behavioral here endmodule

can bridge a mixed input port whose upper connection is compatible with discipline ddiscrete and whose lower connection is compatible with electrical, or a mixed output port whose upper connection is compatible with discipline electrical and whose lower connection is compatible with ddiscrete.

Example 2:

connectmodule a2d (out, in); output out;

input in; ddiscrete out; electrical in;

// insert connect module behavioral here

Copyright © 2009 Accellera Organization, Inc.

162

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