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I am trying to verify 8 bit RW registers and in some of the registers 4 bits are RESERVED lets say [3:0] . My bit bash sequence tries to write in these constant bit and flags me a mismatch error in the DUT and Mirrored Value. How do i stop my bit bash sequence from checking these RESERVED bits of a register. Thanks for your help

Hi, I have a top level reg map set up as below. In my adapter I am trying to retrieve all the registers by address of incoming reg_item in bus2reg function to simulate burst condition. The get_reg_by_offset call returns null every time. I don't understand why the address is not found considering all the registers have unique offsets. Infact I retrieved the base address of the incoming reg_item to check if I can the register before incrementing for next offset, but it cannot find the register with base address. Any help is appreciated. Top register file: TOP_map = create_map(.name("TOP_map"), .base_addr('hFE00), .n_bytes(1),.endian(UVM_LITTLE_ENDIAN),.byte_addressing(1) ); default_map = CONTROL_TOP_map; TOP_map.add_submap(this.int_reg_blk.I2C_INT_map, .offset(8'h7C)); TOP_map.add_submap(this.scan_blk.SCAN_CTL_map, .offset(8'h84)); TOP_map.add_submap(this.ctrl_int_reg_blk.HOR_CTRL_map, .offset(8'h94)); TOP_map.I2C_INT_map.add_hdl_path("********", "RTL"); //didn't want to add proprietary code paths get_reg_by_offset call uvm_reg_item in_item = get_item(); base_addr = in_item.map.get_base_addr(); if(!(in_item.map.get_reg_by_offset(base_addr))) `uvm_error(get_type_name(), "Register not found in reg map") else registers[i] = in_item.map.get_reg_by_offset(base_addr+1);

Hi all, I got a question regarding RAL. Assuming there are 2 registers A and B whose width are 8 bits and 16 bits respectively and the bus width is 8 as well. The two UVM registers are created by new(name, 8, UVM_NO_COVERAGE) and new(name, 16, UVM_NO_COVERAGE) for defining their own width. Register A and B locate at address 0 and 1-2 as the address is byte aligned. An user defined register map is created uvm_reg_map my_map = create_map("my_map", 0, 1, UVM_LITTLE_ENDIAN, 1); my_map.add_reg(reg_A, 0, "RW"); my_map.add_reg(reg_B, 1, "RW"); After reg_B.write(status, 16'habcd, .path(UVM_FRONTDOOR)), I would expect 2 transactions with 8 bits each appearing on the bus. However, there is only one access of h'cd to address 1. The other one never comes and it ends up throwing an error "There are 1 incomplete register transactions still pending completion" which is caused by a check on outstanding register accesses pending in predictor in check phase. I tried to find out how the original data value in uvm_reg_item gets split in reg2bus() function. It seems correct that the original data in uvm_reg_item is h'abcd and split to h'cd in uvm_reg_bus_op. But again the other part of data does not come. Also tried to search for answer from other places, for instance the same issue here https://verificationacademy.com/forums/uvm/how-handle-registers-are-wider-bus, it didn't help much unfortunately. If you have any clue about this, please leave your comments. Thanks.

Hi All, I am facing an issue: One of the register field is configured as : field_a.configure(this, 12, 17, "RO", 0, 12'h0, 1, 0, 1); field_a.set_compare(UVM_NO_CHECK); While doing a reset test, first I reset model then start test. But test fails with : UVM_ERROR -- value read from DUT (0x0000000080001e00) does not match mirrored value (0x00000000XxxXfe00) Basically the fields declared as RO and UVM_NO_CHECK goes X ? Any idea what I am missing or doing wrong ? Thanks.

I have recently modeled registers as simple unions to represent bitfields, for example: typedef union { struct { uint32_t ADDRESS:5; uint32_t RESERVED:26; uint32_t ENABLE:1; } b; uint32_t w; } register_type; which facilitates the access to either the complete word or a bitfield. The interesting part comes when I try to check if the register value has changed, is there a more elegant way of doing this than polling in if or while statements for each register's value? I need to do this for a lot of them so I was wondering if modeling this using sc_bv provides a built-in event I could use in a SC_METHOD sensitivity list? example: typedef union { struct { sc_bv<5> ADDRESS; sc_bv<26> RESERVED; sc_bv<1> ENABLE; } b; uint32_t w; } register_type; and then do something like: register_type Reg; ... SC_METHOD(some_method); sensitive << Reg.b.ENABLE; ... some_method(){ ... } Any pointers or ideas are greatly appreciated

Hi , To whom may correspond I think there is some kind of error in the UVM 1.1d register model. I have been experimenting with the UVM register model and i have seen the following code in uvm_reg_map.svh task uvm_reg_map::do_bus_write (uvm_reg_item rw, uvm_sequencer_base sequencer, uvm_reg_adapter adapter); uvm_reg_addr_t addrs[$]; uvm_reg_map system_map = get_root_map(); int unsigned bus_width = get_n_bytes(); uvm_reg_byte_en_t byte_en = -1; uvm_reg_map_info map_info; int n_bits; int lsb; int skip; int unsigned curr_byte; int n_access_extra, n_access; int n_bits_init; Xget_bus_infoX(rw, map_info, n_bits_init, lsb, skip); addrs=map_info.addr; // if a memory, adjust addresses based on offset if (rw.element_kind == UVM_MEM) foreach (addrs[i]) addrs[i] = addrs[i] + map_info.mem_range.stride * rw.offset; foreach (rw.value[val_idx]) begin: foreach_value uvm_reg_data_t value = rw.value[val_idx]; /* calculate byte_enables */ if (rw.element_kind == UVM_FIELD) begin int temp_be; int idx; n_access_extra = lsb%(bus_width*8); n_access = n_access_extra + n_bits_init; temp_be = n_access_extra; value = value << n_access_extra; while(temp_be >= 8) begin byte_en[idx++] = 0; temp_be -= 8; end temp_be += n_bits_init; while(temp_be > 0) begin byte_en[idx++] = 1; temp_be -= 8; end byte_en &= (1<<idx)-1; for (int i=0; i<skip; i++) void'(addrs.pop_front()); while (addrs.size() > (n_bits_init/(bus_width*8) + 1)) void'(addrs.pop_back()); end curr_byte=0; n_bits= n_bits_init; The code continues but the interesting part is already there. Lets assume we have a register with 4 bytes and 1byte per address granularity (byte_addressing). Now, we do a FIELD access of 8bits length (the first byte of a register). The field is configured "individual_accessible, so UVM should only access that FIELD. The reg2bus should generate that byte request to be written. In other words, the vector "addrs" should have only one byte address. Going to the code, i see that initially the addrs has the 4 address ( the whole register) and when it comes to the "if (rw.element_kind == UVM_FIELD) begin" and it will pop_back()/remove all the exceeding bytes that doesn't need to complete "n_bits_init" of the field access. The problem is here: UVM has //while (addrs.size() > (n_bits_init/(bus_width*8) + 1)) and i think it should be while (addrs.size() > ((n_bits_init-1)/(bus_width*8) + 1)) //ejonalv possible error in UVM? check That is because in case we want to write 8 bits, it will calculate 8/8+1=2 address in the UVM version, but in fact it should require only 1 address. This is of course applicable for the READ variation. Did i misunderstand something? It is very hard to go through the register model without proper documentation in the code. I am looking forward your answer Best Regards Jonathan

Hi, I am using uvm standard register model , register adapter (bus2reg & reg2bus) to send and receive transaction to ral model and DUT. and it is working fine if i do single read and write.(means i perform the 32 bit read n write using reg.read(status,address,data)reg.write(status,address,data)) My challange is that i have to perform the more than 32 bit transaction which performs the read and write on multiple registers, If there any way to use the same reg.read/write method to perform more than one register

Hi Guys, I am using UVM Register model to mimmick RTL's register implementation. Some registers are not implemented in RTL which are going to be connected to output port of some other module. I have got a HDL path of register as an output port declaration of some module. Something like: The HDL path is: "tb_top.dut_u.interrupt_module_u.o_ext_interrupt" o_ext_interrupt is declared as output port inside interrupt_module, which is not connected to any other wire or register. Can this output port's value be changed by writing to it via UVM BACKDOOR ? I am using following API: register_name.write(status,data,UVM_BACKDOOR,default_map); I dont see any change in value in the register. I think it is happening because the destination (o_ext_interrupt) is output of the module. I am using Cadence's simulator: irun. Please help if anyone is aware of such issue. Regards, Vismay.