mikpe.pdp10-tools/include/pdp10-opcodes.h
2015-04-19 18:28:27 +02:00

242 lines
8.4 KiB
C

/*
* pdp10-opcodes.h
* Copyright (C) 2013-2015 Mikael Pettersson
*
* This file is part of pdp10-tools.
*
* pdp10-tools is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* pdp10-tools is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with pdp10-tools. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* Word Representation
* ===================
*
*
* 11111111112222222222333333
* 012345678901234567890123456789012345
* +------------------------------------+
* | |
* +------------------------------------+
*
* The basic storage unit is a 36-bit wide word. Its bits are numbered 0
* to 35, in left-to-right order, with bit 0 being the most significant
* and bit 35 the least significant. (Similar to IBM's bit numbering but
* opposite to most modern processors.)
*
* The architecture supports sub-word storage units via special instructions
* and specially formatted "byte" pointers, where a byte may be from 0 to 36
* bits wide. Incrementing a byte pointer moves it right over a word towards
* its less significant bits, implying a big-endian storage model.
*
* A 72-bit long integer is composed of two adjacent words. It stores the most
* significant bits in first word (lower address) and the least significant bits
* in the second word (higher address), again implying a big-endian storage model.
*
*
* Instruction Representation
* ==========================
*
* Basic instructions are stored in 36-bit words with the following format:
*
* 111 1 1111 112222222222333333
* 012345678 9012 3 4567 890123456789012345
* +---------+----+-+----+------------------+
* | opcode | A |I| X | Y |
* +---------+----+-+----+------------------+
* 9 bits 4 1 4 18 bits
*
* A 9-bit opcode is stored in the high 9 bits.
* A is a 4-bit field specifying the accumulator (a register).
* I is a 1-bit field specifying indirect addressing.
* X is a 4-bit field specifying the index register.
* Y is an 18-bit field specifying an address or offset.
*
* E, the effective addreess, is computed from I, X, and Y.
*
* In some instructions A contains further opcode bits.
*
* In some instructions A is unused and should be zero.
*
* Instructions that not compute an effective address E
* should have I, X, and Y set to zero.
*
* IO instructions have a slightly different format:
*
* 111 1 1111 112222222222333333
* 012 3456789 012 3 4567 890123456789012345
* +---+-------+---+-+----+------------------+
* |op1| device|op2|I| X | Y |
* +---+-------+---+-+----+------------------+
* 3 7 bits 3 1 4 18 bits
*
* The op1 field is all-bits-one (7), the device field addresses the selected device,
* and the op2 field specifies the operation. Both devices internal to the processor
* and devices attached via external buses can be accessed.
*
* Some non-IO instructions also have a 7 in their high three bits.
*
* Extended instructions consist of two separate instruction words:
*
* A:
* 111 1 1111 112222222222333333
* 012345678 9012 3 4567 890123456789012345
* +---------+----+-+----+------------------+
* | 0123 | A |I| X | Y |
* +---------+----+-+----+------------------+
* 9 bits 4 1 4 18 bits
*
* E0:
* 111 1 1111 112222222222333333
* 012345678 9012 3 4567 890123456789012345
* +---------+----+-+----+------------------+
* | xopcode |0000|I| X | Y |
* +---------+----+-+----+------------------+
* 9 bits 4 1 4 18 bits
*
* The first word is stored at address A in the instruction stream in the basic
* format with opcode 0123. The second word is stored at the effective address
* E0 specified by the the first word. Its accumulator field is unused and must
* be zero for compatibility with future extensions.
*/
/*
* Known PDP10 CPU models, each represented by a distinct bit value.
*
* These are combined with bit-wise 'and', 'or', and 'not' operations
* to form sets of CPU models, used to check if a given mnemonic or
* opcode is available for a selected set of CPUs.
*/
enum {
/*
* DEC processors.
*/
PDP10_NONE = 0,
PDP6_166 = 1 << 0, /* DEC PDP-6 Type 166 Arithmetic Processor */
PDP10_KA10 = 1 << 1, /* DEC PDP-10 KA10 */
PDP10_KA10_ITS = 1 << 2, /* DEC PDP-10 KA10, ITS microcode */
PDP10_KI10 = 1 << 3, /* DEC PDP-10 KI10 */
PDP10_KL10 = 1 << 4, /* DEC PDP-10 KL10 */
PDP10_KL10_ITS = 1 << 5, /* DEC PDP-10 KL10, ITS microcode */
PDP10_KL10_271 = 1 << 6, /* DEC PDP-10 KL10, microcode version >= 271 (many extensions) */
PDP10_KS10 = 1 << 7, /* DEC PDP-10 KS10 */
PDP10_KS10_ITS = 1 << 8, /* DEC PDP-10 KS10, ITS microcode */
PDP10_KC10 = 1 << 9, /* DEC PDP-10 KC10 (Jupiter, full extended addressing) */
PDP10_KD10 = 1 << 10, /* DEC PDP-10 KD10 (Minnow, KS10 extended to match KC10 specs) */
/*
* XKL Processors.
*
* The XKL-2 is believed to have been built, and to contain some instruction set
* extensions, but no details are known about it at this time.
*/
PDP10_XKL1 = 1 << 11, /* XKL TOAD-1 XKL-1, KL10 clone with KC10-like full extended addressing */
/*
* Other clones, not yet supported.
*
* System Concepts SC-20, SC-25, SC-30M, SC-40 (KC10-like)
*
* Foonly F-1, F-2, F-3, F-4 (KI10/KL10-hybrid)
*
* Xerox PARC MAXC (KI10-like?)
*/
/*
* Convenience constants for combinations of CPU models.
*/
PDP10_ALL = PDP10_XKL1 | (PDP10_XKL1 - 1), /* XXX: depends on XKL1 being last above */
PDP10_KL10_271up = PDP10_KL10_271 | PDP10_XKL1,
PDP10_KL10any = PDP10_KL10 | PDP10_KL10_ITS | PDP10_KL10_271up,
PDP10_KL10up = PDP10_KL10any | PDP10_KS10,
PDP10_KI10_to_KL10 = PDP10_KI10 | PDP10_KL10any,
PDP10_KI10up = PDP10_KI10 | PDP10_KL10up,
PDP10_KA10any = PDP10_KA10 | PDP10_KA10_ITS,
PDP10_KA10up = PDP10_KA10any | PDP10_KI10up,
PDP10_KA10_to_KI10 = PDP10_KA10 | PDP10_KI10, /* XXX: should that be KA10_any? */
PDP10_KA10_to_KL10 = PDP10_KA10_to_KI10 | PDP10_KL10any,
PDP10_not_KS10_or_XKL1 = PDP10_ALL & ~(PDP10_KS10 | PDP10_XKL1), /* XXX: should that be KS10_any? */
PDP10_ITS = PDP10_KA10_ITS | PDP10_KL10_ITS | PDP10_KS10_ITS,
PDP6_166_to_PDP10_KI10 = PDP6_166 | PDP10_KA10_to_KI10,
};
typedef unsigned short pdp10_cpu_models_t;
/*
* Device names for IO instructions.
*/
struct pdp10_cpu_device {
const char *name;
unsigned char device; /* device field in bits 3-9 of IO instructions */
pdp10_cpu_models_t models;
};
const struct pdp10_cpu_device *
pdp10_cpu_device_from_name(pdp10_cpu_models_t models, const char *name);
/*
* Instructions.
*/
enum {
/* Each instruction belongs to exactly one of these primary categories,
which determine how the high 13 bits are to be interpreted: */
/* XXX: change this to separate mutually exclusive bits to simplify usage */
PDP10_INSN_BASIC = 0,
PDP10_INSN_A_OPCODE = 1,
PDP10_INSN_A_UNUSED = 2,
PDP10_INSN_IO = 3,
/* Flag set to indicate that E is unused. */
PDP10_INSN_E_UNUSED = 4,
/* Flag set to indicate that this is the second word of an extended instruction. */
PDP10_INSN_EXTENDED = 8,
};
typedef unsigned char pdp10_insn_fmt_t;
struct pdp10_insn {
const char *name;
/*
* The high13 field is 13 bits, formatted as:
* <9 bit opcode><0000> BASIC, A_UNUSED
* <9 + 4 bit opcode> A_OPCODE
* <111><0000000><3 bit op> IO
*
* An extended instruction uses the BASIC format with opcode 0123 for
* the first word, and the A_UNUSED | EXTENDED format for the second word.
*/
unsigned short high13;
pdp10_insn_fmt_t fmt;
pdp10_cpu_models_t models;
};
/* for assembly */
const struct pdp10_insn *
pdp10_insn_from_name(pdp10_cpu_models_t models, const char *name);
/* for disassembly */
const struct pdp10_insn *
pdp10_insn_from_high13(pdp10_cpu_models_t models, unsigned int high13, int extended);