Add some parameter types, make parameters a dynamic size without harming cpu readablity too much

2 files changed, 83 insertions, 30 deletions

diff --git a/cpu/instructions/overview.txt b/cpu/instructions/overview.txt
index 280c845..6ec50d3 100644
--- a/cpu/instructions/overview.txt
+++ b/cpu/instructions/overview.txt
@@ -21,18 +21,26 @@ Dynamic VLIW
 		size_of_instructions // size so it won't have to parse each to find where the immediate references start
 		for each:
 			opcode
-			num_instructions
-			for each * params per instruction:
+			size_of_params // size for similar reason as to the above
+			if size_of_params == 0:
+				num_instructions
+			for each param:
+				value (see ./parameter.txt for details)
+
+		has_shared_immediate_references
+		if has_shared_immediate_references:
+			size_of_immediate_references
+			for each:
 				value
-		size_of_immediate_references
-		for each:
-			value
-		num_flag_save_definitions
-		for each:
-			instruction index in queue
-			which flags to save (1 bit per flag type available)
-			where to save them
-			bitwise offset in the destination (log2(bits_for_current_mode) bits)
+
+		has_flag_save_definitions
+		if has_flag_save_definitions:
+			num_flag_save_definitions
+			for each:
+				instruction index in queue
+				which flags to save (1 bit per flag type available)
+				where to save them
+				bitwise offset in the destination (log2(bits_for_current_mode) bits)
 
 	A minimum of <n> instructions per queue must be accepted by all CPUs
 		TODO: define n
diff --git a/cpu/instructions/parameter.txt b/cpu/instructions/parameter.txt
index 311c00a..b50266a 100644
--- a/cpu/instructions/parameter.txt
+++ b/cpu/instructions/parameter.txt
@@ -1,36 +1,81 @@
-n: min number of bits to be able to represent all parameter types
-y: min size required to represent each power of two value less than or equal to the current mode (in bytes, and greater than or equal to 1)
-x: n + y + max([min size to represent each valid offset into the immediate value array], [min size to represent all registers])
+NOTE: `required' refers to what the specification allows, not what the specific CPU allows. Format is not to be implementation dependent.
+
+n: min number of bits required to be able to represent all parameter types
+x: min size required to represent each power of two value less than or equal to the current mode (in bytes, and greater than or equal to 1)
+y: min size to specify a particular segment register
 
 Binary format:
-	type[n], data[x]
+	type[n], data[<type dependent>]
 
 
 Types:
-	Short immediate reference:
-		Value is placed directly in the data section
+	Single immediate reference:
+		Data size: x + [size of immediate value]
+		data[0 to x-1]:
+			Size of immediate value
+		data[x to end]:
+			Raw value
 
-	Immediate reference:
-		data[n to x-y-1]:
-			size of immediate value
+	Shared immediate reference:
+		Data size: x + [minimum size required to represent an offset in the immediate references section]
+		data[0 to x-1]:
+			Size of immediate value
 
-		data[x-y to x-1]:
-			byte offset into the array of immediate values
+		data[x to end]:
+			Offset into the array of immediate values
 
 	Register:
-		data[n to x-y-1]:
-			how much of the register to use
+		Data size: x + [minimum size required to specify any register]
+		data[0 to x-1]:
+			How much of the register to use
+
+		data[x to end]:
+			Which register to use
 
-		data[x-y to x-1]:
-			which register to use
+	Memory at single immediate reference:
+		Uses RAM pointed to by the value as obtained in `single immediate reference` above
+		SS0 will be used for filling in the segment with unspecified bits
+		Prepends n bits to the data:
+			data[0 to n-1]:
+				Size of memory to use
 
-	Memory at immediate reference:
-		Uses RAM pointed to by the value as obtained in `immediate reference` above
-		Size is specified by data[0 to n-1]
+	Memory at shared immediate reference:
+		Uses RAM pointed to by the value as obtained in `shared immediate reference` above
+		SS0 will be used for filling in the segment with unspecified bits
+		Prepends n bits to the data:
+			data[0 to n-1]:
+				Size of memory to use
 
 	Memory at register:
 		Uses RAM pointed to by the value as obtained in `register` above
-		Size is specified by data[0 to n-1]
+		SS0 will be used for filling in the segment with unspecified bits
+		Prepends n bits to the data:
+			data[0 to n-1]:
+				Size of memory to use
+
+	Memory at single immediate reference with segment override:
+		Uses RAM pointed to by the value as obtained in `single immediate reference` above
+		Prepends n + y bits to the data:
+			data[0 to n-1]:
+				Size of memory to use
+			data[n to n+y-1]:
+				Which segment register to use
+
+	Memory at shared immediate reference with segment override:
+		Uses RAM pointed to by the value as obtained in `shared immediate reference` above
+		Prepends n + y bits to the data:
+			data[0 to n-1]:
+				Size of memory to use
+			data[n to n+y-1]:
+				Which segment register to use
+
+	Memory at register with segment override:
+		Uses RAM pointed to by the value as obtained in `register` above
+		Prepends n + y bits to the data:
+			data[0 to n-1]:
+				Size of memory to use
+			data[n to n+y-1]:
+				Which segment register to use
 
 	TODO: Will add more later