1 files changed, 58 insertions, 0 deletions

diff --git a/hdl/defs.svh b/hdl/defs.svh
new file mode 100644
index 0000000..ea8dbc1
--- /dev/null
+++ b/hdl/defs.svh
@@ -0,0 +1,58 @@
+`define RAM_ADDRESS_BITS    23
+`define RAM_BYTE_BITS       8
+`define RAM_WORD_BYTES      2
+`define RAM_LINE_WORDS      1
+
+`define PDP_ADDRESS_BITS    15
+
+`define UART_BYTE_BITS      8
+
+`define TAG_BITS            1
+
+typedef bit             [`RAM_ADDRESS_BITS-1:0]                         ram_word_address_t;
+typedef bit             [`RAM_ADDRESS_BITS-1:$clog2(`RAM_LINE_WORDS)]   ram_line_address_t;
+typedef bit             [`RAM_BYTE_BITS-1:0]                            ram_byte_t;
+typedef ram_byte_t      [`RAM_WORD_BYTES-1:0]                           ram_word_t;
+typedef ram_word_t      [`RAM_LINE_WORDS-1:0]                           ram_line_t;
+typedef bit             [$clog2(`RAM_WORD_BYTES):0]                     ram_word_mask_t;
+typedef ram_word_mask_t [`RAM_LINE_WORDS-1:0]                           ram_line_mask_t;
+
+typedef bit             [$clog2(`RAM_WORD_BYTES+1):0]                   ram_byte_count_t;
+typedef bit             [$clog2(`RAM_LINE_WORDS+1):0]                   ram_word_count_t;
+
+typedef bit             [`RAM_ADDRESS_BITS-1:`PDP_ADDRESS_BITS]         ram_pdp_address_space_t;
+
+typedef bit             [`PDP_ADDRESS_BITS-1:0]                         pdp_word_address_t;
+typedef bit             [`PDP_ADDRESS_BITS-1:$clog2(`RAM_LINE_WORDS)]   pdp_line_address_t;
+
+typedef bit             [`TAG_BITS-1:0]                                 tag_t;
+
+typedef bit             [`UART_BYTE_BITS-1:0]                           uart_byte_t;
+
+typedef struct {
+    ram_line_address_t  address;
+    bit                 write;
+    ram_line_t          data;
+    ram_line_mask_t     mask;
+    tag_t               tag;
+} ram_command_t;
+
+typedef struct {
+    ram_line_address_t  address;
+    ram_line_t          data;
+    tag_t               tag;
+} ram_read_response_t;
+
+typedef struct {
+    pdp_line_address_t  address;
+    bit                 write;
+    ram_line_t          data;
+    ram_line_mask_t     mask;
+    tag_t               tag;
+} pdp_command_t;
+
+typedef struct {
+    pdp_line_address_t  address;
+    ram_line_t          data;
+    tag_t               tag;
+} pdp_read_response_t;