diff options
author | Paul Selkirk <paul@psgd.org> | 2015-03-31 16:24:39 -0400 |
---|---|---|
committer | Paul Selkirk <paul@psgd.org> | 2015-03-31 16:24:39 -0400 |
commit | a40c577dcc9a7db667a57aba74668ac5c6737eae (patch) | |
tree | 9a2c8336bec81d7a92b0a9d215f4c81d65dfd387 /src | |
parent | 755bd6fcfe68a69b035d062b794ea326c30a6de0 (diff) |
Don't delay register reads in eim_regs.
Diffstat (limited to 'src')
-rw-r--r-- | src/rtl/eim_regs.v | 75 |
1 files changed, 37 insertions, 38 deletions
diff --git a/src/rtl/eim_regs.v b/src/rtl/eim_regs.v index 09a51dc..5903ee6 100644 --- a/src/rtl/eim_regs.v +++ b/src/rtl/eim_regs.v @@ -70,9 +70,9 @@ 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; + - //---------------------------------------------------------------- // Concurrent connectivity for ports etc. //---------------------------------------------------------------- @@ -80,43 +80,42 @@ module comm_regs //---------------------------------------------------------------- - // Access Handler + // storage registers for mapping memory to core interface //---------------------------------------------------------------- - always @(posedge clk) - // - if (rst) - reg_dummy <= {32{1'b0}}; - 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 @ (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 + + 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 |