Home » AMD Manuals » Processors » AMD AMD-K6-2/400 » Manual Viewer

AMD AMD-K6-2/400 User Guide - Page 262

FloatingPoint and MMX™/3DNow!™ Instruction Compatibility, Registers, Exceptions

Add to My Manuals
Save this manual to your list of manuals

Page 262 highlights

Preliminary Information AMD-K6™-2E+ Embedded Processor Data Sheet 23542A/0-September 2000 more information on 3DNow! instructions, see the 3DNow!™ Technology Manual, order# 21928. For more information on the 3DNow! technology DSP extensions, see the AMD Extensions to the 3DNow!™ and MMX™ Instructions Sets Manual, order# 22466. The multimedia execution unit can execute MMX instructions in a single processor clock. All MMX and 3DNow! arithmetic instructions are pipelined for higher performance. To increase performance, the processor is designed to simultaneously decode all MMX and 3DNow! instructions with most other instructions. 11.3 Floating-Point and MMX™/3DNow!™ Instruction Compatibility Registers The eight 64-bit MMX registers (which are also utilized by 3DNow! instructions) are mapped on the floating-point stack. This enables backward compatibility with all existing software. For example, the register saving event that is performed by operating systems during task switching requires no changes to the operating system. The same support provided in an operating system's interrupt 7 handler (Device Not Available) for saving and restoring the floating-point registers also supports saving and restoring the MMX registers. Exceptions There are no new exceptions defined for supporting the MMX and 3DNow! instructions. All exceptions that occur while decoding or executing an MMX or 3DNow! instruction are handled in existing exception handlers without modification. FERR# and IGNNE# MMX instructions and 3DNow! instructions do not generate f l o a t i n g -p o i n t e x c e p t i o n s . H oweve r, i f a n u n m a s ke d floating-point exception is pending, the processor asserts FERR# at the instruction boundary of the next floating-point instruction, MMX instruction, 3DNow! instruction or WAIT instruction. The sampling of IGNNE# asserted only affects processor o p e ra t i o n d u r i n g t h e ex e c u t i o n o f a n e r ro r -s e n s i t ive f l oa t i n g -po i n t i n st r u c ti on , MMX i n st r u c t i on , 3D N ow ! instruction or WAIT instruction when the NE bit in CR0 is set to 0. 240 Floating-Point and Multimedia Execution Units Chapter 11

Section	Page
IF YOU HAVE QUESTIONS, WE\	3
Contents	5
List of Figures	9
List of Tables	13
Revision History	17
About this Data Sheet	19
1 AMDK6™2E+ Embedded Processor	23
1.1 AMDK6™2E+ Embedded Processor Features	25
1.2 Process Technology	29
1.3 Super7™ Platform	30
2 Internal Architecture	33
2.1 Microarchitecture Overview	33
2.2 Cache, Instruction Prefetch, and Predecode Bits	38
2.3 Instruction Fetch and Decode	39
2.4 Centralized Scheduler	43
2.5 Execution Units	44
2.6 BranchPrediction Logic	47
3 Software Environment	49
3.1 Registers	49
3.2 ModelSpecific Registers (MSR)	66
3.3 Memory Management Registers	76
3.4 Paging	78
3.5 Descriptors and Gates	81
3.6 Exceptions and Interrupts	84
3.7 Instructions Supported by the AMDK6™2E+ Processor	85
4 Logic Symbol Diagram	113
5 Signal Descriptions	115
5.1 Signal Terminology	115
5.2 A20M# (Address Bit 20 Mask)	116
5.3 A[31:3] (Address Bus)	117
5.4 ADS# (Address Strobe)	118
5.5 ADSC# (Address Strobe Copy)	118
5.6 AHOLD (Address Hold)	119
5.7 AP (Address Parity)	120
5.8 APCHK# (Address Parity Check)	121
5.9 BE[7:0]# (Byte Enables)	122
5.10 BF[2:0] (Bus Frequency)	123
5.11 BOFF# (Backoff)	124
5.12 BRDY# (Burst Ready)	125
5.13 BRDYC# (Burst Ready Copy)	126
5.14 BREQ (Bus Request)	126
5.15 CACHE# (Cacheable Access)	127
5.16 CLK (Clock)	127
5.17 D/C# (Data/Code)	128
5.18 D[63:0] (Data Bus)	129
5.19 DP[7:0] (Data Parity)	130
5.20 EADS# (External Address Strobe)	131
5.21 EWBE# (External Write Buffer Empty)	132
5.22 FERR# (FloatingPoint Error)	133
5.23 FLUSH# (Cache Flush)	134
5.24 HIT# (Inquire Cycle Hit)	135
5.25 HITM# (Inquire Cycle Hit To Modified Line)	135
5.26 HLDA (Hold Acknowledge)	136
5.27 HOLD (Bus Hold Request)	137
5.28 IGNNE# (Ignore Numeric Exception)	138
5.29 INIT (Initialization)	139
5.30 INTR (Maskable Interrupt)	140
5.31 INV (Invalidation Request)	140
5.32 KEN# (Cache Enable)	141
5.33 LOCK# (Bus Lock)	142
5.34 M/IO# (Memory or I/O)	143
5.35 NA# (Next Address)	144
5.36 NMI (NonMaskable Interrupt)	145
5.37 PCD (Page Cache Disable)	146
5.38 PCHK# (Parity Check)	147
5.39 PWT (Page Writethrough)	148
5.40 RESET (Reset)	149
5.41 RSVD (Reserved)	150
5.42 SCYC (Split Cycle)	151
5.43 SMI# (System Management Interrupt)	152
5.44 SMIACT# (System Management Interrupt Active)	153
5.45 STPCLK# (Stop Clock)	154
5.46 TCK (Test Clock)	155
5.47 TDI (Test Data Input)	155
5.48 TDO (Test Data Output)	155
5.49 TMS (Test Mode Select)	156
5.50 TRST# (Test Reset)	156
5.51 VCC2DET (VCC2 Detect)	157
5.52 VCC2H/L# (VCC2 High/Low)	158
5.53 VID[4:0] (Voltage Identification)	159
5.54 W/R# (Write/Read)	160
5.55 WB/WT# (Writeback or Writethrough)	161
5.56 Pin Tables by Type	162
5.57 Bus Cycle Definitions	164
6 AMD PowerNow!™ Technology	165
6.1 Enhanced Power Management Features	165
6.2 Dynamic Core Frequency and Core Voltage Control	172
7 Bus Cycles	175
7.1 Timing Diagrams	175
7.2 Bus States	177
7.3 Memory Reads and Writes	180
7.4 I/O Read and Write	188
7.5 Inquire and Bus Arbitration Cycles	190
7.6 Special Bus Cycles	212
8 Poweron Configuration and Initialization	221
8.1 Signals Sampled During the Falling Transition of RESET	221
8.2 RESET Requirements	222
8.3 State of Processor After RESET	222
8.4 State of Processor After INIT	225
9 Cache Organization	227
9.1 MESI States in the L1 Data Cache and L2 Cache	229
9.2 Predecode Bits	230
9.3 Cache Operation	230
9.4 Cache Disabling and Flushing	233
9.5 L2 Cache Testing	235
9.6 CacheLine Fills	235
9.7 CacheLine Replacements	236
9.8 Write Allocate	237
9.9 Prefetching	242
9.10 Cache States	243
9.11 Cache Coherency	244
9.12 Writethrough and Writeback Coherency States	249
9.13 A20M# Masking of Cache Accesses	249
10 Write Merge Buffer	251
10.1 EWBE# Control	251
10.2 Memory Type Range Registers	253
10.3 Memory-Range Restrictions	255
10.4 Examples	257
11 FloatingPoint and Multimedia Execution Units	259
11.1 FloatingPoint Execution Unit	259
11.2 Multimedia and 3DNow!™ Execution Units	261
11.3 FloatingPoint and MMX™/3DNow!™ Instruction Compatibility	262
12 System Management Mode (SMM)	263
12.1 SMM Operating Mode and Default Register Values	263
12.2 SMM StateSave Area	265
12.3 SMM Revision Identifier	267
12.4 SMM Base Address	268
12.5 Halt Restart Slot	268
12.6 I/O Trap Doubleword	269
12.7 I/O Trap Restart Slot	270
12.8 Exceptions, Interrupts, and Debug in SMM	272
13 Test and Debug	273
13.1 BuiltIn SelfTest (BIST)	273
13.2 ThreeState Test Mode	274
13.3 BoundaryScan Test Access Port (TAP)	275
13.4 Cache Inhibit	285
13.5 L2 Cache and Tag Array Testing	286
13.6 Debug	290
14 Clock Control	297
14.1 Clock Control States	297
14.2 Halt State	300
14.3 Stop Grant State	300
14.4 Stop Grant Inquire State	302
14.5 EPM Stop Grant State	303
14.6 Stop Clock State	305
15 Electrical Data	307
15.1 Operating Ranges	308
15.2 Absolute Ratings	309
15.3 DC Characteristics	309
15.4 Power Dissipation	311
15.5 Power and Grounding	313
16 Signal Switching Characteristics	317
16.1 CLK Switching Characteristics	318
16.2 Clock Switching Characteristics for 100MHz Bus Operation	318
16.3 Clock Switching Characteristics for 66MHz Bus Operation	319
16.4 Valid Delay, Float, Setup, and Hold Timings	320
16.5 Output Delay Timings for 100MHz Bus Operation	320
16.6 Input Setup and Hold Timings for 100MHz Bus Operation	322
16.7 Output Delay Timings for 66MHz Bus Operation	324
16.8 Input Setup and Hold Timings for 66MHz Bus Operation	326
16.9 RESET and Test Signal Timing	328
16.10 Timing Diagrams	331
17 Thermal Design	335
17.1 Package Thermal Specifications	335
17.2 Measuring Case Temperature	339
17.3 Layout and Airflow Considerations	339
18 Pin Designations	343
18.1 Pins Designations for CPGA Package	344
18.2 Pins Designations for OBGA Package	348
19 Package Specifications	353
19.1 321Pin Staggered CPGA Package Specification	353
19.2 349Ball OBGA Package Specification	354
20 Ordering Information	355

Match case Limit results 1 per page

240

Floating-Point and Multimedia Execution Units

Chapter 11

AMD-K6™-2E+ Embedded Processor Data Sheet

23542A/0—September 2000

Preliminary Information

more information on 3DNow! instructions, see the

3DNow!™

Technology Manual

, order# 21928. For more information on the

3DNow! technology DSP extensions, see the

AMD Extensions to

the 3DNow!™ and MMX™ Instructions Sets Manual

, order#

22466.

The multimedia execution unit can execute MMX instructions

in a single processor clock. All MMX and 3DNow! arithmetic

instructions are pipelined for higher performance. To increase

performance, the processor is designed to simultaneously

decode all MMX and 3DNow! instructions with most other

instructions.

11.3

Floating-Point and MMX™/3DNow!™ Instruction Compatibility

Registers

The eight 64-bit MMX registers (which are also utilized by

3DNow! instructions) are mapped on the floating-point stack.

This enables backward compatibility with all existing software.

For example, the register saving event that is performed by

operating systems during task switching requires no changes to

the operating system. The same support provided in an

operating system’s interrupt 7 handler (Device Not Available)

for saving and restoring the floating-point registers also

supports saving and restoring the MMX registers.

Exceptions

There are no new exceptions defined for supporting the MMX

and 3DNow! instructions. All exceptions that occur while

decoding or executing an MMX or 3DNow! instruction are

handled in existing exception handlers without modification.

FERR# and IGNNE#

MMX instructions and 3DNow! instructions do not generate

floating-point exceptions. However, if an unmasked

floating-point exception is pending, the processor asserts

FERR# at the instruction boundary of the next floating-point

instruction, MMX instruction, 3DNow! instruction or WAIT

instruction.

The sampling of IGNNE# asserted only affects processor

operation during the execution of an error-sensitive

floating-point instruction, MMX instruction, 3DNow!

instruction or WAIT instruction when the NE bit in CR0 is set

to 0.

AMD AMD-K6-2/400 User Guide - Page 262

FloatingPoint and MMX™/3DNow!™ Instruction Compatibility, Registers, Exceptions

Page 262 highlights

FloatingPoint and MMX™/3DNow!™ Instruction Compatibility, Registers, Exceptions