== Ports ===========================================================
data in: inCBD
-data in: inAddr.read
-data in: inAddr.write
-data in: inAddr.readMany
-data in: inAddr.writeMany
-data in: inData
-data in: inStride
-data in: inCount
+data in: inAddrRead
+data in: inAddrWrite
+data in: inDataWrite
data out: out
+== TeX ==============================================================
+
+The {\tt Memory} ship represents an interface to a storage space,
+which can be used to read from it or write to it. This storage space
+might be a fast on-chip cache, off chip DRAM, or perhaps even a disk
+drive.
+
+Generally, distinct {\tt Memory} ships do not access the same backing
+storage, although this is not strictly prohibited.
+
+Each {\tt Memory} ship may have multiple {\it interfaces}, numbered
+starting with {\tt 0}. Each interface may have any subset of the
+following docks: {\tt inCBD}, {\tt inAddrRead}, {\tt inAddrWrite},
+{\tt inDataWrite}, and {\tt out}. If {\tt inCBD} or {\tt inAddrRead}
+is present on an interface, then {\tt out} must be present as well.
+If {\tt inAddrWrite} is present then {\tt inDataWrite} must be present
+as well.
+
+Each interface serializes the operations presented to it; this means
+that an interface with both read and write capabilities will not be
+able to read and write concurrently. Instead, a {\tt Memory} ship
+with the ability to read and write concurrently should have two
+interfaces, one which is read-only and one which is write-only.
+
+There may be multiple {\tt Memory} ships which interface to the same
+physical storage space. An implementation of Fleet must provide
+additional documentation to the programmer indicating which {\tt
+Memory} ships correspond to which storage spaces. A single {\tt
+Memory} ship may also access a ``virtual storage space'' formed by
+concatenating multiple physical storage spaces.
+
+\subsection*{Code Bag Fetch}
+
+When a word appears at the {\tt inCBD} port, it is treated as a {\it
+code bag descriptor}, as shown below:
+
+\begin{center}
+\setlength{\bitwidth}{3mm}
+{\tt
+\begin{bytefield}{37}
+ \bitheader[b]{36,6,5,0}\\
+ \bitbox{31}{Address}
+ \bitbox{6}{size}
+\end{bytefield}
+}
+\end{center}
+
+When a word arrives at the {\tt inCBD} port, it is treated as a memory
+read with {\tt inAddrRead=Address}, {\tt inStride=1}, and {\tt
+inCount=size}.
+
+\subsection*{Reading}
+
+When a word is delivered to {\tt inAddrRead}, the word residing in
+memory at that address is provided at {\tt out}. The {\tt c-flag} at
+the {\tt out} port is set to zero.
+
+\subsection*{Writing}
+
+When a word is delivered to {\tt inAddrWrite} and {\tt inDataWrite},
+the word at {\tt inDataWrite} is written to the address specified by
+{\tt inAddrWrite}. Once the word is successfully committed to memory,
+the value {\tt inAddr+inStride} is provided at {\tt out} (that is, the
+address of the next word to be written). The {\tt c-flag} at
+the {\tt out} port is set to one.
+
+\subsection*{To Do}
+
+Stride and count are not implemented.
+
+We need a way to do an ``unordered fetch'' -- a way to tell the memory
+unit to retrieve some block of words in any order it likes. This can
+considerably accelerate fetches when the first word of the region is
+not cached, but other parts are cached. This can also be used for
+dispatching codebags efficiently -- but how will we make sure that
+instructions destined for a given pump are dispatched in the correct
+order (source sequence guarantee)?
+
+A more advanced form would be ``unordered fetch of ordered records''
+-- the ability to specify a record size (in words), the offset of the
+first record, and the number of records to be fetched. The memory
+unit would then fetch the records in any order it likes, but would be
+sure to return the words comprising a record in the order in which
+they appear in memory. This feature could be used to solve the source
+sequence guarantee problem mentioned in the previous paragraph.
+
== Fleeterpreter ====================================================
private long[] mem = new long[0];
- public long readMem(int addr) { return mem[addr]; }
+ public long readMem(int addr) { return addr >= mem.length ? 0 : mem[addr]; }
public void writeMem(int addr, long val) {
if (addr >= mem.length) {
long[] newmem = new long[addr * 2 + 1];
}
mem[addr] = val;
}
-
- public void dispatch(int addr, int size) {
- for(int i=addr; i<addr+size; i++) {
- Instruction instr = ((Interpreter)getFleet()).readInstruction(readMem(i));
- ((Interpreter)getFleet()).dispatch(instr, i);
- }
- }
-
- public void boot(byte[] instructions) {
- Interpreter fleet = (Interpreter)getFleet();
- // load the iscratch and take note of the 0-address INCBD
- long launch = 0;
- for(int i=0; i<instructions.length; i+=6) {
- long word = 0;
- for(int j=0; j<6; j++)
- word = (word << 8) | (instructions[i+j] & 0xff);
- writeMem(i/6, word);
- if (i==0) launch = word;
- }
-
- // dispatch the 0-address INCBD
- int base = (int)(launch >> 6);
- base = base & ~(0xffffffff << 18);
- int size = (int)launch;
- size = size & ~(0xffffffff << 6);
- dispatch(base, size);
+ private Queue<Long> toDispatch = new LinkedList<Long>();
+ public void reset() {
+ super.reset();
+ mem = new long[0];
+ toDispatch.clear();
}
-
public void service() {
+ if (toDispatch.size() > 0) {
+ if (!box_out.readyForDataFromShip()) return;
+ box_out.addDataFromShip(toDispatch.remove());
+ }
if (box_inCBD.dataReadyForShip()) {
long val = box_inCBD.removeDataForShip();
- long addr = val >> 6;
- long size = val & 0x3f;
- dispatch((int)addr, (int)size);
- }
- if (box_inAddr.dataReadyForShip() && box_out.readyForItemFromShip()) {
- Packet packet = box_inAddr.peekPacketForShip();
- if (packet.destination.getDestinationName().equals("read")) {
- box_out.addDataFromShip(readMem((int)box_inAddr.removeDataForShip()));
- } else if (packet.destination.getDestinationName().equals("write") && box_inData.dataReadyForShip()) {
- writeMem((int)box_inAddr.removeDataForShip(),
- box_inData.removeDataForShip());
- box_out.addDataFromShip(0);
- }
+ long addr = ((Interpreter)getFleet()).CBD_OFFSET.getval(val);
+ long size = ((Interpreter)getFleet()).CBD_SIZE.getval(val);
+ for(int i=0; i<size; i++)
+ toDispatch.add(readMem((int)(addr+i)));
+ } else if (box_inAddrWrite.dataReadyForShip() && box_inDataWrite.dataReadyForShip() && box_out.readyForDataFromShip()) {
+ writeMem((int)box_inAddrWrite.removeDataForShip(), box_inDataWrite.removeDataForShip());
+ box_out.addDataFromShip(0,true);
+ } else if (box_inAddrRead.dataReadyForShip() && box_out.readyForDataFromShip()) {
+ box_out.addDataFromShip(readMem((int)box_inAddrRead.removeDataForShip()),false);
}
}
== FleetSim ==============================================================
== FPGA ==============================================================
-`include "macros.v"
-`define BRAM_ADDR_WIDTH 14
-`define BRAM_DATA_WIDTH `DATAWIDTH
-`define BRAM_NAME dscratch_bram
-`include "bram.inc"
-
-module dscratch (clk,
- read_addr_r, read_addr_a_, read_addr_d,
- read_data_r_, read_data_a, read_data_d_,
- write_addr_r, write_addr_a_, write_addr_d,
- write_data_r, write_data_a_, write_data_d,
- write_done_r_, write_done_a, write_done_d_
- );
-
- input clk;
- `input(read_addr_r, read_addr_a, read_addr_a_, [(`DATAWIDTH-1):0], read_addr_d)
- `output(read_data_r, read_data_r_, read_data_a, [(`DATAWIDTH-1):0], read_data_d_)
- `defreg(read_data_d_, [(`DATAWIDTH-1):0], read_data_d)
-
- `input(write_addr_r, write_addr_a, write_addr_a_, [(`DATAWIDTH-1):0], write_addr_d)
- `input(write_data_r, write_data_a, write_data_a_, [(`DATAWIDTH-1):0], write_data_d)
- `output(write_done_r, write_done_r_, write_done_a, [(`DATAWIDTH-1):0], write_done_d_)
- `defreg(write_done_d_, [(`DATAWIDTH-1):0], write_done_d)
-
- reg bram_we;
- wire bram_we_;
- assign bram_we_ = bram_we;
- wire [(`BRAM_DATA_WIDTH-1):0] bram_read_data;
- reg [(`BRAM_ADDR_WIDTH-1):0] bram_write_address;
- wire [(`BRAM_ADDR_WIDTH-1):0] bram_read_address;
- reg [(`BRAM_DATA_WIDTH-1):0] bram_write_data;
- wire [(`BRAM_DATA_WIDTH-1):0] bram_write_data_;
- assign bram_write_data_ = bram_write_data;
- `BRAM_NAME mybram(clk,
- bram_we_, bram_write_address,
- bram_read_address, bram_write_data_,
- not_connected, bram_read_data);
-
- reg send_done;
-
- reg have_read; initial have_read = 0;
- reg read_pending; initial read_pending = 0;
- assign bram_read_address = read_addr_d;
+ `define BRAM_ADDR_WIDTH 14
+ `define BRAM_SIZE (1<<(`BRAM_ADDR_WIDTH))
+
+ reg [(`WORDWIDTH-1):0] ram [((`BRAM_SIZE)-1):0];
+ reg [(`BRAM_ADDR_WIDTH-1):0] addr1;
+ reg [(`BRAM_ADDR_WIDTH-1):0] addr2;
+ reg [(`WORDWIDTH-1):0] out1;
+ reg [(`WORDWIDTH-1):0] out2;
+
+ reg out_w;
+ reg write_flag;
+ reg [(`BRAM_ADDR_WIDTH-1):0] cursor;
+ reg [(`CODEBAG_SIZE_BITS-1):0] counter;
+
+ assign out_d_ = { out_w, out1 };
+
+ // I use "blocking assignment" here in order to facilitate BRAM inference
always @(posedge clk) begin
- bram_we = 0;
- if (send_done) begin
- `onwrite(write_done_r, write_done_a)
- send_done = 0;
- end
- end else begin
- if (!write_addr_r && write_addr_a) write_addr_a = 0;
- if (!write_data_r && write_data_a) write_data_a = 0;
- if (write_addr_r && write_data_r) begin
- write_addr_a = 1;
- write_data_a = 1;
- bram_we = 1;
- send_done = 1;
- bram_write_address = write_addr_d;
- bram_write_data = write_data_d;
- end
- end
+ write_flag = 0;
- if (read_pending) begin
- read_pending <= 0;
- have_read <= 1;
- read_data_d <= bram_read_data;
- end else if (have_read) begin
- `onwrite(read_data_r, read_data_a)
- have_read <= 0;
- end
+ if (rst) begin
+ `reset
+ cursor = 0;
+ counter = 0;
end else begin
- `onread(read_addr_r, read_addr_a)
- // ======= Careful with the timing here! =====================
- // We MUST capture bram_read_data on the very next clock since
- // read_addr_d is free to change after the next clock
- // ===========================================================
- read_pending <= 1;
+ `cleanup
+
+ if (counter!=0) begin
+ if (`out_empty) begin
+ `fill_out
+ out_w = 0;
+ addr1 = cursor;
+ cursor = cursor + 1;
+ counter = counter - 1;
+ end
+
+ end else if (`inCBD_full) begin
+ cursor = inCBD_d[(`WORDWIDTH-1):(`CODEBAG_SIZE_BITS)];
+ counter = inCBD_d[(`CODEBAG_SIZE_BITS-1):0];
+ addr1 = cursor;
+ `drain_inCBD
+
+ end else if (`out_empty && `inAddrRead_full) begin
+ addr1 = inAddrRead_d[(`WORDWIDTH-1):0];
+ `drain_inAddrRead
+ `fill_out
+ out_w = 0;
+
+ end else if (`out_empty && `inAddrWrite_full && `inDataWrite_full) begin
+ write_flag = 1;
+ `drain_inAddrWrite
+ `drain_inDataWrite
+ `fill_out
+ addr2 = inAddrWrite_d[(`WORDWIDTH-1):0];
+ out_w = 1;
+
end
end
+ // this must appear at the end of the block, outside of any if..then's
+ if (write_flag)
+ ram[addr2] <= inDataWrite_d;
+ out1 <= ram[addr1];
+ out2 <= ram[addr2];
end
+
+
+
-endmodule
+== Test ==============================================================
+// Note: this only tests the read/write interfaces, not the inCBD interface
+// FIXME: test c-flag at out dock
+
+// expected output
+#expect 10
+
+// ships required in order to run this code
+#ship debug : Debug
+#ship memory : Memory
+
+memory.inAddrWrite:
+ set word=3;
+ deliver;
+ deliver;
+
+memory.inDataWrite:
+ set word=4;
+ deliver;
+ set word=10;
+ deliver;
+
+memory.inAddrRead:
+ recv token;
+ set word=3;
+ deliver;
+
+memory.out:
+ collect;
+ collect;
+ send token to memory.inAddrRead;
+ collect;
+ send to debug.in;
+
+debug.in:
+ set ilc=*;
+ recv, deliver;
== Constants ========================================================
-== TeX ==============================================================
== Contributors =========================================================
Adam Megacz <megacz@cs.berkeley.edu>
projects / fleet.git / blobdiff