diff options
| author | Paul Selkirk <paul@psgd.org> | 2015-03-31 16:25:31 -0400 |
|---|---|---|
| committer | Paul Selkirk <paul@psgd.org> | 2015-03-31 16:25:31 -0400 |
| commit | f94ca1a732c7f350372bb872741c25b3e6b1bbad (patch) | |
| tree | 9a6a9cc65c9a5309b4e28c4e8815653246cfaf5d /src | |
| parent | ba1b8e736c6e0584a5f8d70a6017374d27d4dec0 (diff) | |
Don't delay register reads in i2c_regs.
Diffstat (limited to 'src')
| -rw-r--r-- | src/rtl/i2c_regs.v | 72 |
1 files changed, 35 insertions, 37 deletions
diff --git a/src/rtl/i2c_regs.v b/src/rtl/i2c_regs.v index e5ddb34..ec1c186 100644 --- a/src/rtl/i2c_regs.v +++ b/src/rtl/i2c_regs.v @@ -70,7 +70,7 @@ module comm_regs reg [31: 0] tmp_read_data; // dummy register to check that you can actually write something - reg [31: 0] reg_dummy; + reg [31: 0] reg_dummy; //---------------------------------------------------------------- @@ -80,44 +80,42 @@ module comm_regs //---------------------------------------------------------------- - // Access Handler + // storage registers for mapping memory to core interface //---------------------------------------------------------------- - always @(posedge clk) - // - if (rst) begin - reg_dummy <= {32{1'b0}}; + always @ (posedge clk or posedge rst) + begin + if (rst) + begin + reg_dummy <= {32{1'b0}}; + end + else if (cs && we) + begin + // write operations + case (address) + ADDR_DUMMY_REG: + reg_dummy <= write_data; + endcase + end end - else if (cs) begin - // - if (we) begin - // - // WRITE handler - // - case (address) - ADDR_DUMMY_REG: - reg_dummy <= write_data; - endcase - // - end else begin - // - // READ handler - // - case (address) - ADDR_CORE_NAME0: - tmp_read_data <= CORE_NAME0; - ADDR_CORE_NAME1: - tmp_read_data <= CORE_NAME1; - ADDR_CORE_VERSION: - tmp_read_data <= CORE_VERSION; - ADDR_DUMMY_REG: - tmp_read_data <= reg_dummy; - // - default: - tmp_read_data <= {32{1'b0}}; // read non-existent locations as zeroes - endcase - // - end - // + + always @* + begin + tmp_read_data = 32'h00000000; + + if (cs && !we) + begin + // read operations + case (address) + ADDR_CORE_NAME0: + tmp_read_data = CORE_NAME0; + ADDR_CORE_NAME1: + tmp_read_data = CORE_NAME1; + ADDR_CORE_VERSION: + tmp_read_data = CORE_VERSION; + ADDR_DUMMY_REG: + tmp_read_data = reg_dummy; + endcase + end end endmodule |