Retro/pcjs
Watch
1
0
Fork
You've already forked pcjs
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Codify reasons for assorted traps

Browse source
This commit is contained in:
Jeff 2016-09-28 15:35:22 -07:00 • committed by Jeff Parsons
commit c858fd0699
7 changed files with 375 additions and 295 deletions
Download patch file Download diff file Expand all files Collapse all files

50
modules/pdp11/lib/cpuops.js
View file

@ -37,6 +37,22 @@ if (NODE) {
var PDP11 = require("./defines");
}
/*
* Decoding starts at the bottom of this file, in op1170(). The basic decoding approach is to
* dispatch on the top 4 bits of the opcode, and if further decoding is required, then dispatch on
* the next 4 bits, and so on (although some of the intermediate levels dispatch only on 2 bits).
*
* Eventually, every opcode should end up either in an opXXX() function or opUndefined(). For
* opcodes that perform a simple read and/or write operation, the entire functionality is handled
* by the opXXX() function. For opcodes that perform a more extensive read/modify/write operation
* (also known as an update operation), those opXXX() functions usually rely on a corresponding
* fnXXX() helper function.
*
* For example, opADD() passes the helper function fnADD() to the appropriate update method. This
* allows the update method to perform the entire read/modify/write operation, because the modification
* is handled by the helper function.
*/
/**
* fnADD(src, dst)
*
@ -803,7 +819,7 @@ PDP11.opBPL = function(opCode)
*/
PDP11.opBPT = function(opCode)
{
this.trap(PDP11.TRAP.BREAKPOINT, 6);
this.trap(PDP11.TRAP.BREAKPOINT, PDP11.REASON.BPT);
this.nStepCycles -= 1;
};
@ -1061,7 +1077,7 @@ PDP11.opDIV = function(opCode)
*/
PDP11.opEMT = function(opCode)
{
this.trap(PDP11.TRAP.EMULATOR, 2);
this.trap(PDP11.TRAP.EMULATOR, PDP11.REASON.EMT);
this.nStepCycles -= 1;
};
@ -1075,7 +1091,7 @@ PDP11.opHALT = function(opCode)
{
if (this.regPSW & PDP11.PSW.CMODE) {
this.regErr |= PDP11.CPUERR.BADHALT;
this.trap(PDP11.TRAP.BUS_ERROR, 46);
this.trap(PDP11.TRAP.BUS_ERROR, PDP11.REASON.HALT);
} else {
this.runState = 3;
this.endBurst();
@ -1115,7 +1131,7 @@ PDP11.opINCB = function(opCode)
*/
PDP11.opIOT = function(opCode)
{
this.trap(PDP11.TRAP.IOT, 8);
this.trap(PDP11.TRAP.IOT, PDP11.REASON.IOT);
this.nStepCycles -= 1;
};
@ -1548,7 +1564,7 @@ PDP11.opSXT = function(opCode)
*/
PDP11.opTRAP = function(opCode)
{
this.trap(PDP11.TRAP.TRAP, 4);
this.trap(PDP11.TRAP.TRAP, PDP11.REASON.TRAP);
this.nStepCycles -= 1;
};
@ -1612,18 +1628,7 @@ PDP11.opXOR = function(opCode)
*/
PDP11.opUndefined = function(opCode)
{
this.trap(PDP11.TRAP.RESERVED, 48);
};
/**
* op1170(opCode)
*
* @this {CPUStatePDP11}
* @param {number} opCode
*/
PDP11.op1170 = function(opCode)
{
PDP11.aOpsXnnn_1170[opCode >> 12].call(this, opCode);
this.trap(PDP11.TRAP.RESERVED, PDP11.REASON.RESERVED);
};
/**
@ -1802,6 +1807,17 @@ PDP11.op8DXn_1170 = function(opCode)
PDP11.aOps8DXn_1170[(opCode >> 6) & 0x3].call(this, opCode);
};
/**
* op1170(opCode)
*
* @this {CPUStatePDP11}
* @param {number} opCode
*/
PDP11.op1170 = function(opCode)
{
PDP11.aOpsXnnn_1170[opCode >> 12].call(this, opCode);
};
PDP11.aOpsXnnn_1170 = [
PDP11.op0Xnn_1170, // 0x0nnn
PDP11.opMOV, // 0x1nnn 01SSDD