Freescale MC7455ARX1000LF Risc microprocessor hardware specification Datasheet

Freescale Semiconductor
MPC7455EC
Rev. 4.1, 02/2005
Technical Data
MPC7455
RISC Microprocessor
Hardware Specifications
The MPC7455 and MPC7445 are implementations of the
PowerPC™ microprocessor family of reduced instruction set
computer (RISC) microprocessors. This document is primarily
concerned with the MPC7455; however, unless otherwise noted,
all information here also applies to the MPC7445. This document
describes pertinent electrical and physical characteristics of the
MPC7455. For functional characteristics of the processor, refer to
the MPC7450 RISC Microprocessor Family User’s Manual. To
locate any published updates for this document, refer to the
website at http://www.freescale.com.
1
Overview
The MPC7455 is the third implementation of the fourth generation
(G4) microprocessors from Freescale. The MPC7455 implements
the full PowerPC 32-bit architecture and is targeted at networking
and computing systems applications. The MPC7455 consists of a
processor core, a 256-Kbyte L2, and an internal L3 tag and
controller which support a glueless backside L3 cache through a
dedicated high-bandwidth interface. The MPC7445 is identical to
the MPC7455 except it does not support the L3 cache interface.
Figure 1 shows a block diagram of the MPC7455.
© Freescale Semiconductor, Inc., 2005. All rights reserved.
Contents
1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2. Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Comparison with the MPC7400, MPC7410,
MPC7450, MPC7451, and MPC7441 . . . . . . . . . . . . . 7
4. General Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5. Electrical and Thermal Characteristics . . . . . . . . . . . 10
6. Pin Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7. Pinout Listings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
8. Package Description . . . . . . . . . . . . . . . . . . . . . . . . . 41
9. System Design Information . . . . . . . . . . . . . . . . . . . 45
10. Document Revision History . . . . . . . . . . . . . . . . . . . 59
11. Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . 60
2
Vector
FPU
External SRAM
(1 or 2 Mbytes)
18-Bit
64-Bit Data
Address (8-Bit Parity)
Not in
MPC7445
Bus Accumulator
128-Bit
L3CR
L3 Cache Controller
Vector
Integer
Unit 1
Line Block 0/1
Tags Status
Vector
Integer
Unit 2
Completes up to three instructions per clock
Completion Queue
(16-Entry)
Completion Unit
Vector
Permute
Unit
VR File
Dispatch
Unit
+++
x÷
Push
36-Bit Address Bus
Bus Accumulator
Castout
Queue
(9)
Bus Store Queue
L2 Prefetch (3)
64-Bit Data Bus
L2 Store Queue (L2SQ)
Snoop Push/
Interventions
L1 Castouts
(4)
Instruction Fetch (2)
Cacheable Store
Request (1)
L1 Load Miss (5)
L1 Load Queue (LLQ)
L1 Service Queues
L1 Store Queue
(LSQ)
64-Bit
FPSCR
64-Bit
FloatingPoint Unit
Reservation
Stations (2)
Completed
Stores
Load Miss
FPR File
16 Rename
Buffers
PA
32-Kbyte
D Cache
32-Kbyte
I Cache
+ x ÷
EA
Tags
Tags
128-Bit (4 Instructions)
L1 Push
256-Kbyte Unified L2 Cache/Cache Controller
Line Block 0 (32-Byte)
Block 1 (32-Byte)
Tags Status
Status
32-Bit
L1 Castout
GPR File
Finished
Stores
+ (EA Calculation)
Load/Store Unit
Reservation
Stations (2-Entry)
DBAT Array
128-Entry
DTLB
Data MMU
SRs
(Original)
Vector Touch Engine
16 Rename
Buffers
32-Bit
Memory Subsystem
32-Bit
Integer
Integer
Integer
Unit
122
Unit
Unit
(3)
Integer
Unit 2
128-Entry
ITLB
IBAT Array
SRs
(Shadow)
Instruction MMU
Vector
Touch
Queue
FPR Issue
(2-Entry/1-Issue)
Instruction Queue
(12-Word)
Reservation
Reservation
Reservation
Station
Station
Station
System Bus Interface
128-Bit
16 Rename
Buffers
Reservation
Stations (2)
LR
BHT (2048-Entry)
VR Issue
(4-Entry/2-Issue)
CTR
BTIC (128-Entry)
Fetcher
GPR Issue
(6-Entry/3-Issue)
Instruction Unit
Branch Processing Unit
Reservation Reservation Reservation Reservation
Station
Station
Station
Station
96-Bit (3 Instructions)
Additional Features
• Time Base Counter/Decrementer
• Clock Multiplier
• JTAG/COP Interface
• Thermal/Power Management
• Performance Monitor
Overview
Figure 1. MPC7455 Block Diagram
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
Features
The core is a high-performance superscalar design supporting a double-precision floating-point unit and a SIMD
multimedia unit. The memory storage subsystem supports the MPX bus protocol and a subset of the 60x bus protocol
to main memory and other system resources. The L3 interface supports 1 or 2 Mbytes of external SRAM for L3
cache data.
Note that the MPC7455 is footprint-compatible with the MPC7450 and MPC7451, and the MPC7445 is
footprint-compatible with the MPC7441.
2
Features
This section summarizes features of the MPC7455 implementation of the PowerPC architecture.
Major features of the MPC7455 are as follows:
•
•
High-performance, superscalar microprocessor
— As many as four instructions can be fetched from the instruction cache at a time
— As many as three instructions can be dispatched to the issue queues at a time
— As many as 12 instructions can be in the instruction queue (IQ)
— As many as 16 instructions can be at some stage of execution simultaneously
— Single-cycle execution for most instructions
— One instruction per clock cycle throughput for most instructions
— Seven-stage pipeline control
Eleven independent execution units and three register files
— Branch processing unit (BPU) features static and dynamic branch prediction
– 128-entry (32-set, four-way set-associative) branch target instruction cache (BTIC), a cache of
branch instructions that have been encountered in branch/loop code sequences. If a target instruction
is in the BTIC, it is fetched into the instruction queue a cycle sooner than it can be made available
from the instruction cache. Typically, a fetch that hits the BTIC provides the first four instructions
in the target stream.
– 2048-entry branch history table (BHT) with two bits per entry for four levels of
prediction—not-taken, strongly not-taken, taken, and strongly taken
– Up to three outstanding speculative branches
– Branch instructions that do not update the count register (CTR) or link register (LR) are often
removed from the instruction stream.
– Eight-entry link register stack to predict the target address of Branch Conditional to Link Register
(bclr) instructions
— Four integer units (IUs) that share 32 GPRs for integer operands
– Three identical IUs (IU1a, IU1b, and IU1c) can execute all integer instructions except multiply,
divide, and move to/from special-purpose register instructions
– IU2 executes miscellaneous instructions including the CR logical operations, integer multiplication
and division instructions, and move to/from special-purpose register instructions
— Five-stage FPU and a 32-entry FPR file
– Fully IEEE 754-1985-compliant FPU for both single- and double-precision operations
– Supports non-IEEE mode for time-critical operations
– Hardware support for denormalized numbers
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
3
Features
•
•
•
•
– Thirty-two 64-bit FPRs for single- or double-precision operands
— Four vector units and 32-entry vector register file (VRs)
– Vector permute unit (VPU)
– Vector integer unit 1 (VIU1) handles short-latency AltiVec™ integer instructions, such as vector add
instructions (vaddsbs, vaddshs, and vaddsws, for example)
– Vector integer unit 2 (VIU2) handles longer-latency AltiVec integer instructions, such as vector
multiply add instructions (vmhaddshs, vmhraddshs, and vmladduhm, for example)
– Vector floating-point unit (VFPU)
— Three-stage load/store unit (LSU)
– Supports integer, floating-point, and vector instruction load/store traffic
– Four-entry vector touch queue (VTQ) supports all four architected AltiVec data stream operations
– Three-cycle GPR and AltiVec load latency (byte, half-word, word, vector) with one-cycle
throughput
– Four-cycle FPR load latency (single, double) with one-cycle throughput
– No additional delay for misaligned access within double-word boundary
– Dedicated adder calculates effective addresses (EAs)
– Supports store gathering
– Performs alignment, normalization, and precision conversion for floating-point data
– Executes cache control and TLB instructions
– Performs alignment, zero padding, and sign extension for integer data
– Supports hits under misses (multiple outstanding misses)
– Supports both big- and little-endian modes, including misaligned little-endian accesses
Three issue queues FIQ, VIQ, and GIQ can accept as many as one, two, and three instructions, respectively,
in a cycle. Instruction dispatch requires the following:
— Instructions can be dispatched only from the three lowest IQ entries—IQ0, IQ1, and IQ2
— A maximum of three instructions can be dispatched to the issue queues per clock cycle
— Space must be available in the CQ for an instruction to dispatch (this includes instructions that are
assigned a space in the CQ but not in an issue queue)
Rename buffers
— 16 GPR rename buffers
— 16 FPR rename buffers
— 16 VR rename buffers
Dispatch unit
— Decode/dispatch stage fully decodes each instruction
Completion unit
— The completion unit retires an instruction from the 16-entry completion queue (CQ) when all
instructions ahead of it have been completed, the instruction has finished execution, and no exceptions
are pending.
— Guarantees sequential programming model (precise exception model)
— Monitors all dispatched instructions and retires them in order
— Tracks unresolved branches and flushes instructions after a mispredicted branch
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
4
Freescale Semiconductor
Features
•
•
•
— Retires as many as three instructions per clock cycle
Separate on-chip L1 instruction and data caches (Harvard architecture)
— 32-Kbyte, eight-way set-associative instruction and data caches
— Pseudo least-recently-used (PLRU) replacement algorithm
— 32-byte (eight-word) L1 cache block
— Physically indexed/physical tags
— Cache write-back or write-through operation programmable on a per-page or per-block basis
— Instruction cache can provide four instructions per clock cycle; data cache can provide four words per
clock cycle
— Caches can be disabled in software
— Caches can be locked in software
— MESI data cache coherency maintained in hardware
— Separate copy of data cache tags for efficient snooping
— Parity support on cache and tags
— No snooping of instruction cache except for icbi instruction
— Data cache supports AltiVec LRU and transient instructions
— Critical double- and/or quad-word forwarding is performed as needed. Critical quad-word forwarding
is used for AltiVec loads and instruction fetches. Other accesses use critical double-word forwarding.
Level 2 (L2) cache interface
— On-chip, 256-Kbyte, eight-way set-associative unified instruction and data cache
— Fully pipelined to provide 32 bytes per clock cycle to the L1 caches
— A total nine-cycle load latency for an L1 data cache miss that hits in L2
— PLRU replacement algorithm
— Cache write-back or write-through operation programmable on a per-page or per-block basis
— 64-byte, two-sectored line size
— Parity support on cache
Level 3 (L3) cache interface (not implemented on MPC7445)
— Provides critical double-word forwarding to the requesting unit
— Internal L3 cache controller and tags
— External data SRAMs
— Support for 1- and 2-Mbyte L3 caches
— Cache write-back or write-through operation programmable on a per-page or per-block basis
— 64-byte (1M) or 128-byte (2M) sectored line size
— Private memory capability for half (1-Mbyte minimum) or all of the L3 SRAM space
— Supports MSUG2 dual data rate (DDR) synchronous Burst SRAMs, PB2 pipelined synchronous Burst
SRAMs, and pipelined (register-register) late write synchronous Burst SRAMs
— Supports parity on cache and tags
— Configurable core-to-L3 frequency divisors
— 64-bit external L3 data bus sustains 64 bits per L3 clock cycle
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
5
Features
•
•
•
•
Separate memory management units (MMUs) for instructions and data
— 52-bit virtual address; 32- or 36-bit physical address
— Address translation for 4-Kbyte pages, variable-sized blocks, and 256-Mbyte segments
— Memory programmable as write-back/write-through, caching-inhibited/caching-allowed, and memory
coherency enforced/memory coherency not enforced on a page or block basis
— Separate IBATs and DBATs (eight each) also defined as SPRs
— Separate instruction and data translation lookaside buffers (TLBs)
– Both TLBs are 128-entry, two-way set-associative, and use LRU replacement algorithm
– TLBs are hardware- or software-reloadable (that is, on a TLB miss a page table search is performed
in hardware or by system software)
Efficient data flow
— Although the VR/LSU interface is 128 bits, the L1/L2/L3 bus interface allows up to 256 bits
— The L1 data cache is fully pipelined to provide 128 bits/cycle to or from the VRs
— L2 cache is fully pipelined to provide 256 bits per processor clock cycle to the L1 cache
— As many as eight outstanding, out-of-order, cache misses are allowed between the L1 data cache and
L2/L3 bus
— As many as 16 out-of-order transactions can be present on the MPX bus
— Store merging for multiple store misses to the same line. Only coherency action taken (address-only)
for store misses merged to all 32 bytes of a cache block (no data tenure needed).
— Three-entry finished store queue and five-entry completed store queue between the LSU and the L1 data
cache
— Separate additional queues for efficient buffering of outbound data (such as castouts and write through
stores) from the L1 data cache and L2 cache
Multiprocessing support features include the following:
— Hardware-enforced, MESI cache coherency protocols for data cache
— Load/store with reservation instruction pair for atomic memory references, semaphores, and other
multiprocessor operations
Power and thermal management
— 1.3-V processor core
— The following three power-saving modes are available to the system:
– Nap—Instruction fetching is halted. Only those clocks for the time base, decrementer, and JTAG
logic remain running. The part goes into the doze state to snoop memory operations on the bus and
then back to nap using a QREQ/QACK processor-system handshake protocol.
– Sleep—Power consumption is further reduced by disabling bus snooping, leaving only the PLL in a
locked and running state. All internal functional units are disabled.
– Deep sleep—When the part is in the sleep state, the system can disable the PLL. The system can then
disable the SYSCLK source for greater system power savings. Power-on reset procedures for
restarting and relocking the PLL must be followed on exiting the deep sleep state.
— Thermal management facility provides software-controllable thermal management. Thermal
management is performed through the use of three supervisor-level registers and an MPC7455-specific
thermal management exception.
— Instruction cache throttling provides control of instruction fetching to limit power consumption
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
6
Freescale Semiconductor
Comparison with the MPC7400, MPC7410, MPC7450, MPC7451, and MPC7441
•
•
•
•
3
Performance monitor can be used to help debug system designs and improve software efficiency
In-system testability and debugging features through JTAG boundary-scan capability
Testability
— LSSD scan design
— IEEE 1149.1 JTAG interface
— Array built-in self test (ABIST)—factory test only
Reliability and serviceability
— Parity checking on system bus and L3 cache bus
— Parity checking on the L2 and L3 cache tag arrays
Comparison with the MPC7400, MPC7410, MPC7450,
MPC7451, and MPC7441
Table 1 compares the key features of the MPC7455 with the key features of the earlier MPC7400, MPC7410,
MPC7450, MPC7451, and MPC7441. To achieve a higher frequency, the number of logic levels per cycle is
reduced. Also, to achieve this higher frequency, the pipeline of the MPC7455 is extended (compared to the
MPC7400), while maintaining the same level of performance as measured by the number of instructions executed
per cycle (IPC).
Table 1. Microarchitecture Comparison
Microarchitectural Specs
MPC7455/MPC7445
MPC7450/MPC7451/
MPC7441
MPC7400/MPC7410
Basic Pipeline Functions
Logic inversions per cycle
18
18
28
Pipeline stages up to execute
5
5
3
Total pipeline stages (minimum)
7
7
4
3 + Branch
3 + Branch
2 + Branch
Pipeline maximum instruction
throughput
Pipeline Resources
Instruction buffer size
12
12
6
Completion buffer size
16
16
8
16, 16, 16
16, 16, 16
6, 6, 6
Renames (integer, float, vector)
Maximum Execution Throughput
SFX
Vector
Scalar floating-point
3
3
2
2 (Any 2 of 4 Units)
2 (Any 2 of 4 Units)
2 (Permute/Fixed)
1
1
1
Out-of-Order Window Size in Execution Queues
SFX integer units
1 Entry × 3 Queues
1 Entry × 3 Queues
1 Entry × 2 Queues
Vector units
In Order, 4 Queues
In Order, 4 Queues
In Order, 2 Queues
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
7
Comparison with the MPC7400, MPC7410, MPC7450, MPC7451, and MPC7441
Table 1. Microarchitecture Comparison (continued)
MPC7455/MPC7445
MPC7450/MPC7451/
MPC7441
MPC7400/MPC7410
In Order
In Order
In Order
BTIC, BHT, Link Stack
BTIC, BHT, Link Stack
BTIC, BHT
128-Entry, 4-Way
128-Entry, 4-Way
64-Entry, 4-Way
2K-Entry
2K-Entry
512-Entry
Link stack depth
8
8
None
Unresolved branches supported
3
3
2
Branch taken penalty (BTIC hit)
1
1
0
Minimum misprediction penalty
6
6
4
Microarchitectural Specs
Scalar floating-point unit
Branch Processing Resources
Prediction structures
BTIC size, associativity
BHT size
Execution Unit Timings (Latency-Throughput)
Aligned load (integer, float, vector)
3-1, 4-1, 3-1
3-1, 4-1, 3-1
2-1, 2-1, 2-1
Misaligned load (integer, float, vector)
4-2, 5-2, 4-2
4-2, 5-2, 4-2
3-2, 3-2, 3-2
9 Data/13 Instruction
9 Data/13 Instruction
9 (11) 1
SFX (aDd Sub, Shift, Rot, Cmp, logicals)
1-1
1-1
1-1
Integer multiply (32 × 8, 32 × 16, 32 × 32)
3-1, 3-1, 4-2
3-1, 3-1, 4-2
2-1, 3-2, 5-4
Scalar float
5-1
5-1
3-1
VSFX (vector simple)
1-1
1-1
1-1
VCFX (vector complex)
4-1
4-1
3-1
VFPU (vector float)
4-1
4-1
4-1
VPER (vector permute)
2-1
2-1
1-1
128-Entry, 2-Way
128-Entry, 2-Way
128-Entry, 2-Way
Hardware + Software
Hardware + Software
Hardware
8/8
4/4
4/4
32K/32K
32K/32K
32K/32K
8-Way
8-Way
8-Way
Locking granularity
Way
Way
Full Cache
Parity on I cache
Word
Word
None
Parity on D cache
Byte
Byte
None
Number of D cache misses (load/store)
5/1
5/1
8 (Any Combination)
4 Streams
4 Streams
4 Streams
L1 miss, L2 hit latency
MMUs
TLBs (instruction and data)
Tablewalk mechanism
Instruction BATs/data BATs
L1 I Cache/D Cache Features
Size
Associativity
Data stream touch engines
On-Chip Cache Features
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
8
Freescale Semiconductor
General Parameters
Table 1. Microarchitecture Comparison (continued)
Microarchitectural Specs
MPC7455/MPC7445
MPC7450/MPC7451/
MPC7441
L2
L2
256-Kbyte/8-Way
256-Kbyte/8-Way
256 Bits
256 Bits
2
2
Byte
Byte
Cache level
Size/associativity
Access width
Number of 32-byte sectors/line
Parity
MPC7400/MPC7410
L2 tags and controller
only (see off-chip cache
support below)
Off-Chip Cache Support 2
Cache level
On-chip tag logical size
Associativity
Number of 32-byte sectors/line
Off-chip data SRAM support
L3
L3
L2
1MB, 2MB
1MB, 2MB
0.5MB, 1MB, 2MB
8-Way
8-Way
2-Way
2, 4
2, 4
1, 2, 4
MSUG2 DDR, LW, PB2 MSUG2 DDR, LW, PB2
Data path width
Direct mapped SRAM sizes
LW, PB2, PB3
64
64
64
1 Mbyte, 2 Mbytes
1 Mbyte, 2 Mbytes
0.5 Mbyte, 1 Mbyte,
2 Mbytes 3
Byte
Byte
Byte
Parity
Notes:
1. Numbers in parentheses are for 2:1 SRAM.
2. Not implemented on MPC7445 or MPC7441.
3. Private memory feature not implemented on MPC7400.
4
General Parameters
The following list provides a summary of the general parameters of the MPC7455:
Technology
Die size
Transistor count
Logic design
Packages
Core power supply
I/O power supply
2.5 V ± 5% DC, or
1.5 V ± 5% DC (L3 interface only)
0.18 µ m CMOS, six-layer metal
8.69 mm × 12.17 mm (106 mm2)
33 million
Fully-static
MPC7445: Surface mount 360 ceramic ball grid array (CBGA)
MPC7455: Surface mount 483 ceramic ball grid array (CBGA)
1.3 V ± 50 mV DC nominal
1.8 V ± 5% DC, or
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
9
Electrical and Thermal Characteristics
5
Electrical and Thermal Characteristics
This section provides the AC and DC electrical specifications and thermal characteristics for the MPC7455.
5.1 DC Electrical Characteristics
The tables in this section describe the MPC7455 DC electrical characteristics. Table 2 provides the absolute
maximum ratings.
Table 2. Absolute Maximum Ratings 1
Characteristic
Symbol
Maximum Value
Unit
Notes
Core supply voltage
VDD
–0.3 to 1.95
V
4
PLL supply voltage
AVDD
–0.3 to 1.95
V
4
BVSEL = 0
OVDD
–0.3 to 1.95
V
3, 6
BVSEL = HRESET or OVDD
OVDD
–0.3 to 2.7
V
3, 7
L3VSEL = ¬HRESET
GVDD
–0.3 to 1.65
V
3, 8
L3VSEL = 0
GVDD
–0.3 to 1.95
V
3, 9
L3VSEL = HRESET or GVDD
GVDD
–0.3 to 2.7
V
3, 10
Processor bus
Vin
–0.3 to OV DD + 0.3
V
2, 5
L3 bus
Vin
–0.3 to GV DD + 0.3
V
2, 5
JTAG signals
Vin
–0.3 to OV DD + 0.3
V
Processor bus
Vin
–0.3 to OV DD + 0.3
V
JTAG signals
Vin
–0.3 to OV DD + 0.3
V
Tstg
–55 to 150
°C
Processor bus supply voltage
L3 bus supply voltage
Input voltage
Input voltage
Storage temperature range
2, 5
Notes:
1. Functional and tested operating conditions are given in Table 4. Absolute maximum ratings are stress ratings only,
and functional operation at the maximums is not guaranteed. Stresses beyond those listed may affect device
reliability or cause permanent damage to the device.
2. Caution: V in must not exceed OVDD or GVDD by more than 0.3 V at any time including during power-on reset.
3. Caution: OVDD/GV DD must not exceed VDD/AVDD by more than 2.0 V during normal operation; this limit may be
exceeded for a maximum of 20 ms during power-on reset and power-down sequences.
4. Caution: V DD/AVDD must not exceed OVDD/GVDD by more than 1.0 V during normal operation; this limit may be
exceeded for a maximum of 20 ms during power-on reset and power-down sequences.
5. Vin may overshoot/undershoot to a voltage and for a maximum duration as shown in Figure 2.
6. BVSEL must be set to 0, such that the bus is in 1.8 V mode.
7. BVSEL must be set to HRESET or 1, such that the bus is in 2.5 V mode.
8. L3VSEL must be set to ¬HRESET (inverse of HRESET), such that the bus is in 1.5 V mode.
9. L3VSEL must be set to 0, such that the bus is in 1.8 V mode.
10.L3VSEL must be set to HRESET or 1, such that the bus is in 2.5 V mode.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
10
Freescale Semiconductor
Electrical and Thermal Characteristics
Figure 2 shows the undershoot and overshoot voltage on the MPC7455.
OVDD/GVDD + 20%
OVDD/GVDD + 5%
OVDD /GVDD
VIH
VIL
GND
GND – 0.3 V
GND – 0.7 V
Not to Exceed 10%
of tSYSCLK
Figure 2. Overshoot/Undershoot Voltage
The MPC7455 provides several I/O voltages to support both compatibility with existing systems and migration to
future systems. The MPC7455 core voltage must always be provided at nominal 1.3 V (see Table 4 for actual
recommended core voltage). Voltage to the L3 I/Os and processor interface I/Os are provided through separate sets
of supply pins and may be provided at the voltages shown in Table 3. The input voltage threshold for each bus is
selected by sampling the state of the voltage select pins at the negation of the signal HRESET. The output voltage
will swing from GND to the maximum voltage applied to the OVDD or GVDD power pins.
Table 3. Input Threshold Voltage Setting
BVSEL Signal
Processor Bus Input
Threshold is Relative to:
L3VSEL Signal 5
L3 Bus Input Threshold is
Relative to:
Notes
0
1.8 V
0
1.8 V
1, 4
¬HRESET
Not Available
¬HRESET
1.5 V
1, 3
HRESET
2.5 V
HRESET
2.5 V
1, 2
1
2.5 V
1
2.5 V
1
Notes:
1. Caution: The input threshold selection must agree with the OVDD/GVDD voltages supplied. See notes in Table 2.
2. To select the 2.5-V threshold option for the processor bus, BVSEL should be tied to HRESET so that the two signals
change state together. Similarly, to select 2.5 V for the L3 bus, tie L3VSEL to HRESET. This is the preferred method
for selecting this mode of operation.
3. Applicable to L3 bus interface only. ¬HRESET is the inverse of HRESET.
4. If used, pulldown resistors should be less than 250 Ω.
5. Not implemented on MPC7445.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
11
Electrical and Thermal Characteristics
Table 4 provides the recommended operating conditions for the MPC7455.
Table 4. Recommended Operating Conditions 1
Recommended Value
Characteristic
Symbol
Unit
Min
Core supply voltage
VDD
1.3 V ± 50 mV
V
PLL supply voltage
AVDD
1.3 V ± 50 mV
V
BVSEL = 0
OVDD
1.8 V ± 5%
V
BVSEL = HRESET or OVDD
OVDD
2.5 V ± 5%
V
L3VSEL = 0
GVDD
1.8 V ± 5%
V
L3VSEL = HRESET or GVDD
GVDD
2.5 V ± 5%
V
L3VSEL = ¬HRESET
GVDD
1.5 V ± 5%
V
Processor bus supply voltage
L3 bus supply voltage
Input voltage
Die-junction temperature
Notes
Max
Processor bus
Vin
GND
OVDD
V
L3 bus
Vin
GND
GVDD
V
JTAG signals
Vin
GND
OVDD
V
Tj
0
105
°C
2
Notes:
1. These are the recommended and tested operating conditions. Proper device operation outside of these conditions
is not guaranteed.
2. This voltage is the input to the filter discussed in Section 9.2, “PLL Power Supply Filtering,” and not necessarily the
voltage at the AVDD pin which may be reduced from VDD by the filter.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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Freescale Semiconductor
Electrical and Thermal Characteristics
Table 5 provides the package thermal characteristics for the MPC7455.
Table 5. Package Thermal Characteristics 6
Value
Characteristic
Symbol
MPC7445
MPC7455
Unit
Notes
Junction-to-ambient thermal resistance, natural
convection
RθJA
22
20
°C/W
1, 2
Junction-to-ambient thermal resistance, natural
convection, four-layer (2s2p) board
RθJMA
14
14
°C/W
1, 3
Junction-to-ambient thermal resistance, 200 ft/min
airflow, single-layer (1s) board
RθJMA
16
15
°C/W
1, 3
Junction-to-ambient thermal resistance, 200 ft/min
airflow, four-layer (2s2p) board
RθJMA
11
11
°C/W
1, 3
Junction-to-board thermal resistance
RθJB
6
6
°C/W
4
Junction-to-case thermal resistance
RθJC
<0.1
<0.1
°C/W
5
Notes:
1. Junction temperature is a function of on-chip power dissipation, package thermal resistance, mounting site (board)
temperature, ambient temperature, airflow, power dissipation of other components on the board, and board thermal
resistance.
2. Per SEMI G38-87 and JEDEC JESD51-2 with the single-layer board horizontal.
3. Per JEDEC JESD51-6 with the board horizontal.
4. Thermal resistance between the die and the printed-circuit board per JEDEC JESD51-8. Board temperature is
measured on the top surface of the board near the package.
5. Thermal resistance between the die and the case top surface as measured by the cold plate method
(MIL SPEC-883 Method 1012.1) with the calculated case temperature. The actual value of RθJC for the part is less
than 0.1°C/W.
6. Refer to Section 9.8, “Thermal Management Information,” for more details about thermal management.
Table 6 provides the DC electrical characteristics for the MPC7455.
Table 6. DC Electrical Specifications
At recommended operating conditions. See Table 4.
Nominal
Bus
Voltage 1
Symbol
Min
Max
Unit
Notes
1.5
VIH
GVDD × 0.65
GV DD + 0.3
V
6
1.8
VIH
OV DD/GVDD × 0.65
OVDD/GV DD + 0.3
V
2.5
VIH
1.7
OVDD/GV DD + 0.3
V
1.5
VIL
–0.3
GVDD × 0.35
V
1.8
VIL
–0.3
OVDD/GVDD × 0.35
V
2.5
VIL
–0.3
0.7
V
SYSCLK input high voltage
—
CVIH
1.4
OV DD + 0.3
V
SYSCLK input low voltage
—
CV IL
–0.3
0.4
V
Characteristic
Input high voltage
(all inputs except SYSCLK)
Input low voltage
(all inputs except SYSCLK)
6
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
13
Electrical and Thermal Characteristics
Table 6. DC Electrical Specifications (continued)
At recommended operating conditions. See Table 4.
Nominal
Bus
Voltage 1
Symbol
Min
Max
Unit
Notes
Input leakage current,
Vin = GVDD/OVDD + 0.3 V
—
Iin
—
30
µA
2, 3
High impedance (off-state) leakage
current, Vin = GVDD/OVDD + 0.3 V
—
ITSI
—
30
µA
2, 3, 5
Output high voltage, IOH = –5 mA
1.5
VOH
GVDD – 0.45
—
V
6
1.8
VOH
OVDD/GV DD – 0.45
—
V
2.5
VOH
1.7
—
V
1.5
VOL
—
0.45
V
1.8
VOL
—
0.45
V
2.5
VOL
—
0.7
V
—
Cin
—
9.5
pF
4
—
8.0
pF
4
Characteristic
Output low voltage, IOL = 5 mA
Capacitance,
Vin = 0 V,
f = 1 MHz
L3 interface
All other inputs
6
Notes:
1. Nominal voltages; see Table 4 for recommended operating conditions.
2. For processor bus signals, the reference is OV DD while GVDD is the reference for the L3 bus signals.
3. Excludes test signals and IEEE 1149.1 boundary scan (JTAG) signals.
4. Capacitance is periodically sampled rather than 100% tested.
5. The leakage is measured for nominal OVDD/GVDD and VDD, or both OVDD/GVDD and VDD must vary in the same
direction (for example, both OVDD and VDD vary by either +5% or –5%).
6. Applicable to L3 bus interface only.
Table 7 provides the power consumption for the MPC7455.
Table 7. Power Consumption for MPC7455
Processor (CPU) Frequency
733 MHz
867 MHz
933 MHz
1 GHz
Unit
Notes
Full-Power Mode
Typical
11.5
12.9
13.6
15.0
W
1, 3
Maximum
17.0
19.0
20.0
22.0
W
1, 2
—
—
W
4
8.0
8.0
W
1, 3
Doze Mode
Typical
—
—
Nap Mode
Typical
8.0
8.0
Sleep Mode
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
14
Freescale Semiconductor
Electrical and Thermal Characteristics
Table 7. Power Consumption for MPC7455 (continued)
Processor (CPU) Frequency
Unit
Notes
7.6
W
1, 3
7.3
W
1, 3
733 MHz
867 MHz
933 MHz
1 GHz
7.6
7.6
7.6
Typical
Deep Sleep Mode (PLL Disabled)
Typical
7.3
7.3
7.3
Notes:
1. These values apply for all valid processor bus and L3 bus ratios. The values do not include I/O supply power (OVDD
and GVDD) or PLL supply power (AVDD). OVDD and GVDD power is system dependent, but is typically <5% of VDD
power. Worst case power consumption for AV DD < 3 mW.
2. Maximum power is measured at nominal VDD (see Table 4) while running an entirely cache-resident, contrived
sequence of instructions which keep the execution units, with or without AltiVec, maximally busy.
3. Typical power is an average value measured at the nominal recommended VDD (see Table 4) and 65°C in a system
while running a typical code sequence.
4. Doze mode is not a user-definable state; it is an intermediate state between full-power and either nap or sleep mode.
As a result, power consumption for this mode is not tested.
5.2 AC Electrical Characteristics
This section provides the AC electrical characteristics for the MPC7455. After fabrication, functional parts are
sorted by maximum processor core frequency as shown in Section 5.2.1, “Clock AC Specifications,” and tested for
conformance to the AC specifications for that frequency. The processor core frequency is determined by the bus
(SYSCLK) frequency and the settings of the PLL_CFG[0:4] signals. Parts are sold by maximum processor core
frequency; see Section 11, “Ordering Information.”
5.2.1
Clock AC Specifications
Table 8 provides the clock AC timing specifications as defined in Figure 3.
Table 8. Clock AC Timing Specifications
At recommended operating conditions. See Table 4.
Maximum Processor Core Frequency
Characteristic
Symbol
733 MHz
867 MHz
933 MHz
1 GHz
Min
Max
Min
Max
Min
Max
Min
Max
Unit
Notes
Processor frequency
fcore
500
733
500
867
500
933
500
1000
MHz
1
VCO frequency
fVCO
1000
1466
1000
1734
1000
1866
1000
2000
MHz
1
SYSCLK frequency
fSYSCLK
33
133
33
133
33
133
33
133
MHz
1
SYSCLK cycle time
tSYSCLK
7.5
30
7.5
30
7.5
30
7.5
30
ns
SYSCLK rise and fall time
tKR, tKF
—
1.0
—
1.0
—
1.0
—
1.0
ns
2
SYSCLK duty cycle
measured at OVDD/2
tKHKL/
tSYSCLK
40
60
40
60
40
60
40
60
%
3
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
15
Electrical and Thermal Characteristics
Table 8. Clock AC Timing Specifications (continued)
At recommended operating conditions. See Table 4.
Maximum Processor Core Frequency
Characteristic
Symbol
733 MHz
867 MHz
933 MHz
1 GHz
Unit
Notes
Min
Max
Min
Max
Min
Max
Min
Max
SYSCLK jitter
—
± 150
—
± 150
—
± 150
—
± 150
ps
4, 6
Internal PLL relock time
—
100
—
100
—
100
—
100
µs
5
Notes:
1. Caution: The SYSCLK frequency and PLL_CFG[0:4] settings must be chosen such that the resulting SYSCLK
(bus) frequency, CPU (core) frequency, and PLL (VCO) frequency do not exceed their respective maximum or
minimum operating frequencies. Refer to the PLL_CFG[0:4] signal description in Section 9.1, “PLL Configuration,”
for valid PLL_CFG[0:4] settings.
2. Rise and fall times for the SYSCLK input measured from 0.4 to 1.4 V.
3. Timing is guaranteed by design and characterization.
4. This represents total input jitter—short term and long term combined—and is guaranteed by design.
5. Relock timing is guaranteed by design and characterization. PLL-relock time is the maximum amount of time
required for PLL lock after a stable VDD and SYSCLK are reached during the power-on reset sequence. This
specification also applies when the PLL has been disabled and subsequently re-enabled during sleep mode. Also
note that HRESET must be held asserted for a minimum of 255 bus clocks after the PLL-relock time during the
power-on reset sequence.
6. The SYSCLK driver’s closed loop jitter bandwidth should be <500 kHz at –20 dB. The bandwidth must be set low
to allow cascade connected PLL-based devices to track SYSCLK drivers with the specified jitter.
Figure 3 provides the SYSCLK input timing diagram.
SYSCLK
VM
VM
tKHKL
VM
CVIH
CVIL
tKR
tKF
tSYSCLK
VM = Midpoint Voltage (OVDD/2)
Figure 3. SYSCLK Input Timing Diagram
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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Electrical and Thermal Characteristics
5.2.2
Processor Bus AC Specifications
Table 9 provides the processor bus AC timing specifications for the MPC7455 as defined in Figure 4 and Figure 5.
Timing specifications for the L3 bus are provided in Section 5.2.3, “L3 Clock AC Specifications.”
Table 9. Processor Bus AC Timing Specifications 1
At recommended operating conditions. See Table 4.
All Speed Grades
Parameter
Symbol 2
Unit
Notes
Min
Max
tAVKH
2.0
—
tIVKH
2.0
—
tMVKH
2.0
—
tAXKH
0
—
tIXKH
0
—
tMXKH
0
—
Output valid times:
A[0:35], AP[0:4], GBL, TBST, TSIZ[0:2], TT[0:3], WT, CI
TS
D[0:63], DP[0:7]
ARTRY/SHD0/SHD1
BR, CKSTP_OUT, DRDY, HIT, PMON_OUT, QREQ]
tKHAV
tKHTSV
tKHDV
tKHARV
tKHOV
—
—
—
—
—
2.5
2.5
2.5
2.5
2.5
Output hold times:
A[0:35], AP[0:4], GBL, TBST, TSIZ[0:2], TT[0:3], WT, CI
TS
D[0:63], DP[0:7]
ARTRY/SHD0/SHD1
BR, CKSTP_OUT, DRDY, HIT, PMON_OUT, QREQ
tKHAX
tKHTSX
tKHDX
tKHARX
tKHOX
0.5
0.5
0.5
0.5
0.5
—
—
—
—
—
SYSCLK to output enable
tKHOE
0.5
—
ns
SYSCLK to output high impedance (all except TS, ARTRY,
SHD0, SHD1)
tKHOZ
—
3.5
ns
SYSCLK to TS high impedance after precharge
tKHTSPZ
—
1
tSYSCLK
3, 4, 5
Maximum delay to ARTRY/SHD0/SHD1 precharge
tKHARP
—
1
tSYSCLK
3, 5,
6, 7
Input setup times:
A[0:35], AP[0:4], GBL, TBST, TSIZ[0:2], TT[0:3], D[0:63],
DP[0:7]
AACK, ARTRY, BG, CKSTP_IN, DBG, DTI[0:3], QACK, TA,
TBEN, TEA, TS, EXT_QUAL, PMON_IN, SHD[0:1]
BMODE[0:1], BVSEL, L3VSEL
Input hold times:
A[0:35], AP[0:4], GBL, TBST, TSIZ[0:2], TT[0:3], D[0:63],
DP[0:7]
AACK, ARTRY, BG, CKSTP_IN, DBG, DTI[0:3], QACK, TA,
TBEN, TEA, TS,EXT_QUAL, PMON_IN, SHD[0:1]
BMODE[0:1], BVSEL, L3VSEL
ns
8
ns
8
ns
ns
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
17
Electrical and Thermal Characteristics
Table 9. Processor Bus AC Timing Specifications 1 (continued)
At recommended operating conditions. See Table 4.
All Speed Grades
Symbol 2
Parameter
SYSCLK to ARTRY/SHD0/SHD1 high impedance after
precharge
tKHARPZ
Min
Max
—
2
Unit
Notes
tSYSCLK
3, 5,
6, 7
Notes:
1. All input specifications are measured from the midpoint of the signal in question to the midpoint of the rising edge of the input
SYSCLK. All output specifications are measured from the midpoint of the rising edge of SYSCLK to the midpoint of the signal
in question. All output timings assume a purely resistive 50-Ω load (see Figure 4). Input and output timings are measured at
the pin; time-of-flight delays must be added for trace lengths, vias, and connectors in the system.
2. The symbology used for timing specifications herein follows the pattern of t(signal)(state)(reference)(state) for inputs and
t(reference)(state)(signal)(state) for outputs. For example, tIVKH symbolizes the time input signals (I) reach the valid state (V)
relative to the SYSCLK reference (K) going to the high (H) state or input setup time. And tKHOV symbolizes the time from
SYSCLK(K) going high (H) until outputs (O) are valid (V) or output valid time. Input hold time can be read as the time that the
input signal (I) went invalid (X) with respect to the rising clock edge (KH) (note the position of the reference and its state for
inputs) and output hold time can be read as the time from the rising edge (KH) until the output went invalid (OX).
3. tsysclk is the period of the external clock (SYSCLK) in ns. The numbers given in the table must be multiplied by the period of
SYSCLK to compute the actual time duration (in ns) of the parameter in question.
4. According to the bus protocol, TS is driven only by the currently active bus master. It is asserted low then precharged high
before returning to high impedance as shown in Figure 6. The nominal precharge width for TS is 0.5 × tSYSCLK, that is, less
than the minimum tSYSCLK period, to ensure that another master asserting TS on the following clock will not contend with the
precharge. Output valid and output hold timing is tested for the signal asserted. Output valid time is tested for precharge. The
high-impedance behavior is guaranteed by design.
5. Guaranteed by design and not tested.
6. According to the bus protocol, ARTRY can be driven by multiple bus masters through the clock period immediately following
AACK. Bus contention is not an issue because any master asserting ARTRY will be driving it low. Any master asserting it low
in the first clock following AACK will then go to high impedance for one clock before precharging it high during the second
cycle after the assertion of AACK. The nominal precharge width for ARTRY is 1.0 tSYSCLK; that is, it should be high
impedance as shown in Figure 6 before the first opportunity for another master to assert ARTRY. Output valid and output
hold timing is tested for the signal asserted. The high-impedance behavior is guaranteed by design.
7. According to the MPX bus protocol, SHD0 and SHD1 can be driven by multiple bus masters beginning the cycle of TS. Timing
is the same as ARTRY, that is, the signal is high impedance for a fraction of a cycle, then negated for up to an entire cycle
(crossing a bus cycle boundary) before being three-stated again. The nominal precharge width for SHD0 and SHD1 is 1.0
tSYSCLK. The edges of the precharge vary depending on the programmed ratio of core-to-bus (PLL configurations).
8. BMODE[0:1] and BVSEL are mode select inputs and are sampled before and after HRESET negation. These paramenters
represent the input setup and hold times for each sample. These values are guaranteed by design and not tested. These
inputs must remain stable after the second sample. See Figure 5 for sample timing.
Figure 4 provides the AC test load for the MPC7455.
Output
Z0 = 50 Ω
RL = 50 Ω
OVDD/2
Figure 4. AC Test Load
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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Freescale Semiconductor
Electrical and Thermal Characteristics
Figure 5 provides the mode select input timing diagram for the MPC7455.
VM
VM
SYSCLK
HRESET
Mode Signals
Firs t Sample
Second Sample
VM = Midpoint Voltage (OVDD/2)
Figure 5. Mode Input Timing Diagram
Figure 6 provides the input/output timing diagram for the MPC7455.
SYSCLK
VM
VM
tAVKH
tIVKH
tMVKH
VM
tAXKH
tIXKH
tMXKH
All Inputs
All Outputs
(Except TS,
ARTRY, SHD0, SHD1)
tKHAV
tKHAX
tKHDV
tKHDX
tKHOV
tKHOX
tKHOE
tKHOZ
All Outputs
(Except TS,
ARTRY, SHD0, SHD1)
tKHTSPZ
tKHTSV
tKHTSX
tKHTSV
TS
tKHARPZ
tKHARV
ARTRY,
SHD0,
SHD1
tKHARP
tKHARX
VM = Midpoint Voltage (OVDD/2)
Figure 6. Input/Output Timing Diagram
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
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Electrical and Thermal Characteristics
5.2.3 L3 Clock AC Specifications
The L3_CLK frequency is programmed by the L3 configuration register (L3CR[6:8]) core-to-L3 divisor ratio. See
Table 18 for example core and L3 frequencies at various divisors. Table 10 provides the potential range of L3_CLK
output AC timing specifications as defined in Figure 7.
The maximum L3_CLK frequency is the core frequency divided by two. Given the high core frequencies available
in the MPC7455, however, most SRAM designs will be not be able to operate in this mode using current technology
and, as a result, will select a greater core-to-L3 divisor to provide a longer L3_CLK period for read and write access
to the L3 SRAMs. Therefore, the typical L3_CLK frequency shown in Table 10 is considered to be the practical
maximum in a typical system. The maximum L3_CLK frequency for any application of the MPC7455 will be a
function of the AC timings of the MPC7455, the AC timings for the SRAM, bus loading, and printed-circuit board
trace length, and may be greater or less than the value given in Table 10.
Freescale is similarly limited by system constraints and cannot perform tests of the L3 interface on a socketed part
on a functional tester at the maximum frequencies of Table 10. Therefore, functional operation and AC timing
information are tested at core-to-L3 divisors which result in L3 frequencies at 200 MHz or less.
Table 10. L3_CLK Output AC Timing Specifications
At recommended operating conditions. See Table 4.
All Speed Grades
Parameter
Symbol
Min
Typ
Max
Unit
Notes
1
L3 clock frequency
fL3_CLK
75
250
—
MHz
L3 clock cycle time
tL3_CLK
—
4.0
13.3
ns
L3 clock duty cycle
tCHCL/tL3_CLK
50
%
2
L3 clock output-to-output skew (L1_CLK0 to
L1_CLK1)
tL3CSKW1
—
—
200
ps
3
L3 clock output-to-output skew (L1_CLK[0:1]
to L1_ECHO_CLK[2:3])
tL3CSKW2
—
—
100
ps
4
—
—
±50
ps
5
L3 clock jitter
Notes:
1. The maximum L3 clock frequency will be system dependent. See Section 5.2.3, “L3 Clock AC Specifications,” for
an explanation that this maximum frequency is not functionally tested at speed by Freescale.
2. The nominal duty cycle of the L3 output clocks is 50% measured at midpoint voltage.
3. Maximum possible skew between L3_CLK0 and L3_CLK1. This parameter is critical to the address and control
signals which are common to both SRAM chips in the L3.
4. Maximum possible skew between L3_CLK0 and L3_ECHO_CLK1 or between L3_CLK1 and L3_ECHO_CLK3 for
PB2 or late write SRAM. This parameter is critical to the write data signals which are separately latched onto each
SRAM part by these pairs of signals.
5. Guaranteed by design and not tested. The input jitter on SYSCLK affects L3 output clocks and the L3
address/data/control signals equally and, therefore, is already comprehended in the AC timing and does not have
to be considered in the L3 timing analysis. The clock-to-clock jitter shown here is uncertainty in the internal clock
period caused by supply voltage noise or thermal effects. This must be accounted for, along with clock skew, in
any L3 timing analysis.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
20
Freescale Semiconductor
Electrical and Thermal Characteristics
The L3_CLK timing diagram is shown in Figure 7.
tL3CF
tL3CR
tL3_CLK
tCHCL
L3_CLK0
VM
VM
VM
L3_CLK1
VM
VM
VM
VM
tL3CSKW1
For PB2 or Late Write:
L3_ECHO_CLK1
VM
VM
VM
VM
tL3CSKW2
L3_ECHO_CLK3
VM
VM
VM
VM
tL3CSKW2
Figure 7. L3_CLK_OUT Output Timing Diagram
5.2.4
L3 Bus AC Specifications
The MPC7455 L3 interface supports three different types of SRAM: source-synchronous, double data rate (DDR)
MSUG2 SRAM, late write SRAMs, and pipeline burst (PB2) SRAMs. Each requires a different protocol on the L3
interface and a different routing of the L3 clock signals. The type of SRAM is programmed in L3CR[22:23] and the
MPC7455 then follows the appropriate protocol for that type. The designer must connect and route the L3 signals
appropriately for each type of SRAM. Following are some observations about the chip-to-SRAM interface.
•
•
•
•
The routing for the point-to-point signals (L3_CLK[0:1], L3DATA[0:63], L3DP[0:7], and
L3_ECHO_CLK[0:3]) to a particular SRAM should be delay matched. If necessary, the length of traces can
be altered in order to intentionally skew the timing and provide additional setup or hold time margin.
For a 1-Mbyte L3, use address bits 16:0 (bit 0 is LSB).
No pull-up resistors are required for the L3 interface.
For high speed operations, L3 interface address and control signals should be a ‘T’ with minimal stubs to
the two loads; data and clock signals should be point-to-point to their single load. Figure 8 shows the AC
test load for the L3 interface.
Output
Z0 = 50 Ω
RL = 50 Ω
GVDD/2
Figure 8. AC Test Load for the L3 Interface
In general, if routing is short, delay-matched, and designed for incident wave reception and minimal reflection, there
is a high probability that the AC timing of the MPC7455 L3 interface will meet the maximum frequency operation
of appropriately chosen SRAMs. This is despite the pessimistic, guard-banded AC specifications (see Table 12,
Table 13, and Table 14), the limitations of functional testers described in Section 5.2.3, “L3 Clock AC
Specifications,” and the uncertainty of clocks and signals which inevitably make worst-case critical path timing
analysis pessimistic.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
21
Electrical and Thermal Characteristics
More specifically, certain signals within groups should be delay-matched with others in the same group while
intergroup routing is less critical. Only the address and control signals are common to both SRAMs and additional
timing margin is available for these signals. The double-clocked data signals are grouped with individual clocks as
shown in Figure 9 or Figure 11, depending on the type of SRAM. For example, for the MSUG2 DDR SRAM (see
Figure 9); L3DATA[0:31], L3DP[0:3], and L3_CLK[0] form a closely coupled group of outputs from the MPC7455;
while L3DATA[0:15], L3DP[0:1], and L3_ECHO_CLK[0] form a closely coupled group of inputs.
The MPC7450 RISC Microprocessor Family User’s Manual refers to logical settings called ‘sample points’ used in
the synchronization of reads from the receive FIFO. The computation of the correct value for this setting is
system-dependent and is described in the MPC7450 RISC Microprocessor Family User’s Manual. Three
specifications are used in this calculation and are given in Table 11. It is essential that all three specifications are
included in the calculations to determine the sample points, as incorrect settings can result in errors and
unpredictable behavior. For more information, see the MPC7450 RISC Microprocessor Family User’s Manual.
Table 11. Sample Points Calculation Parameters
Parameter
Symbol
Max
Unit
Notes
Delay from processor clock to internal_L3_CLK
tAC
3/4
tL3_CLK
1
Delay from internal_L3_CLK to L3_CLKn output pins
tCO
3
ns
2
Delay from L3_ECHO_CLKn to receive latch
tECI
3
ns
3
Notes:
1. This specification describes a logical offset between the internal clock edge used to launch the L3 address and
control signals (this clock edge is phase-aligned with the processor clock edge) and the internal clock edge used to
launch the L3_CLKn signals. With proper board routing, this offset ensures that the L3_CLKn edge will arrive at the
SRAM within a valid address window and provide adequate setup and hold time. This offset is reflected in the L3
bus interface AC timing specifications, but must also be separately accounted for in the calculation of sample points
and, thus, is specified here.
2. This specification is the delay from a rising or falling edge on the internal_L3_CLK signal to the corresponding rising
or falling edge at the L3CLKn pins.
3. This specification is the delay from a rising or falling edge of L3_ECHO_CLKn to data valid and ready to be sampled
from the FIFO.
5.2.4.1 L3 Bus AC Specifications for DDR MSUG2 SRAMs
When using DDR MSUG2 SRAMs at the L3 interface, the parts should be connected as shown in Figure 9.
Outputs from the MPC7455 are actually launched on the edges of an internal clock phase-aligned to SYSCLK
(adjusted for core and L3 frequency divisors). L3_CLK0 and L3_CLK1 are this internal clock output with 90° phase
delay, so outputs are shown synchronous to L3_CLK0 and L3_CLK1. Output valid times are typically negative
when referenced to L3_CLKn because the data is launched one-quarter period before L3_CLKn to provide adequate
setup time at the SRAM after the delay-matched address, control, data, and L3_CLKn signals have propagated
across the printed-wiring board.
Inputs to the MPC7455 are source-synchronous with the CQ clock generated by the DDR MSUG2 SRAMs. These
CQ clocks are received on the L3_ECHO_CLKn inputs of the MPC7455. An internal circuit delays the incoming
L3_ECHO_CLKn signal such that it is positioned within the valid data window at the internal receiving latches. This
delayed clock is used to capture the data into these latches which comprise the receive FIFO. This clock is
asynchronous to all other processor clocks. This latched data is subsequently read out of the FIFO synchronously to
the processor clock. The time between writing and reading the data is set by the using the sample point settings
defined in the L3CR register.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
22
Freescale Semiconductor
Electrical and Thermal Characteristics
Table 12 provides the L3 bus interface AC timing specifications for the configuration as shown in Figure 9,
assuming the timing relationships shown in Figure 10 and the loading shown in Figure 8.
Table 12. L3 Bus Interface AC Timing Specifications for MSUG2
At recommended operating conditions. See Table 4.
All Speed Grades 8
Parameter
Symbol
L3OH0 = 0, L3OH1 = 0 L3OH0 = 0, L3OH1 =1 L3OH0 = 1, L3OH1 = 0 L3OH0 = 1, L3OH1 = 1 Unit Notes
Min
Max
Min
Max
Min
Max
Min
Max
L3_CLK rise
and fall time
tL3CR,
tL3CF
—
1.0
—
1.0
—
1.0
—
1.0
ns
1
Setup times:
Data and
parity
tL3DVEH,
tL3DVEL
– 0.1
—
– 0.1
—
– 0.1
—
– 0.1
—
ns
2, 3,
4
Input hold
times: Data
and parity
tL3DXEH,
tL3DXEL
tL3_CLK/4
+ 0.30
—
tL3_CLK/4
+ 0.30
—
tL3_CLK/4
+ 0.30
—
tL3_CLK/4
+ 0.30
—
ns
2, 4
Valid times:
Data and
parity
tL3CHDV,
tL3CLDV
—
(– tL3_CLK/4)
+ 0.60
—
(– tL3_CLK/4)
+ 0.40
—
(– tL3_CLK/4)
+ 0.20
—
(– tL3_CLK/4)
+ 0.00
ns
5, 6,
7
Valid times:
All other
outputs
tL3CHOV
—
tL3_CLK/4
+ 0.80
—
tL3_CLK/4
+ 0.60
—
tL3_CLK/4
+ 0.40
—
tL3_CLK/4
+ 0.20
ns
5, 7
Output hold
times: Data
and parity
tL3CHDX,
tL3CLDX,
tL3_CLK/4
– 0.40
—
tL3_CLK/4
– 0.60
—
tL3_CLK/4
– 0.80
—
tL3_CLK/4
– 1.00
—
ns
5, 6,
7
Output hold
times: All
other outputs
tL3CHOX
tL3_CLK/4
– 0.20
—
tL3_CLK/4
– 0.40
—
tL3_CLK/4
– 0.60
—
tL3_CLK/4
– 0.80
—
ns
5, 7
L3_CLK to
high
impedance:
Data and
parity
tL3CLDZ
—
tL3_CLK/2
—
tL3_CLK/2
—
tL3_CLK/2
—
tL3_CLK/2
ns
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
23
Electrical and Thermal Characteristics
Table 12. L3 Bus Interface AC Timing Specifications for MSUG2 (continued)
At recommended operating conditions. See Table 4.
All Speed Grades 8
Parameter
L3_CLK to
high
impedance:
All other
outputs
Symbol
tL3CHOZ
L3OH0 = 0, L3OH1 = 0 L3OH0 = 0, L3OH1 =1 L3OH0 = 1, L3OH1 = 0 L3OH0 = 1, L3OH1 = 1 Unit Notes
Min
Max
Min
Max
Min
Max
Min
Max
—
tL3_CLK/4
+ 2.0
—
tL3_CLK/4
+ 2.0
tL3_CLK/4
+ 2.0
—
tL3_CLK/4
+ 2.0
—
ns
Notes:
1. Rise and fall times for the L3_CLK output are measured from 20% to 80% of GVDD.
2. For DDR, all input specifications are measured from the midpoint of the signal in question to the midpoint voltage of the rising
or falling edge of the input L3_ECHO_CLKn (see Figure 10). Input timings are measured at the pins.
3. For DDR, the input data will typically follow the edge of L3_ECHO_CLKn as shown in Figure 10. For consistency with other
input setup time specifications, this will be treated as negative input setup time.
4. tL3_CLK/4 is one-fourth the period of L3_CLKn. This parameter indicates that the MPC7455 can latch an input signal that is
valid for only a short time before and a short time after the midpoint between the rising and falling (or falling and rising) edges
of L3_ECHO_CLKn at any frequency.
5. All output specifications are measured from the midpoint voltage of the rising (or for DDR write data, also the falling) edge
of L3_CLK to the midpoint of the signal in question. The output timings are measured at the pins. All output timings assume
a purely resistive 50-Ω load (see Figure 8).
6. For DDR, the output data will typically lead the edge of L3_CLKn as shown in Figure 10. For consistency with other output
valid time specifications, this will be treated as negative output valid time.
7. tL3_CLK/4 is one-fourth the period of L3_CLKn. This parameter indicates that the specified output signal is actually launched
by an internal clock delayed in phase by 90°. Therefore, there is a frequency component to the output valid and output hold
times such that the specified output signal will be valid for approximately one L3_CLK period starting three-fourths of a clock
prior to the edge on which the SRAM will sample it and ending one-fourth of a clock period after the edge it will be sampled.
8. These configuration bits allow the AC timing of the L3 interface to be altered via software. L3OH0 = L2CR[12],
L30H1 = L3CR[12]. Revisions of the MPC7455 not described by this document may implement these bits differently. See
Section 11.1, “Part Numbers Fully Addressed by This Document,” and Section 11.2, “Part Numbers Not Fully Addressed by
This Document,” for more information on which devices are addressed by this document.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
24
Freescale Semiconductor
Electrical and Thermal Characteristics
Figure 9 shows the typical connection diagram for the MPC7455 interfaced to MSUG2 SRAMs such as the
Freescale MCM64E836.
L3ADDR[17:0]
MPC7455
L3_CNTL[0]
L3_CNTL[1]
Denotes
Receive (SRAM
to MPC7455)
Aligned Signals
L3_ECHO_CLK[0]
{L3DATA[0:15], L3DP[0:1]}
L3_CLK[0]
{L3DATA[16:31], L3DP[2:3]}
L3_ECHO_CLK[1]
Denotes
Transmit
(MPC7455 to
SRAM)
Aligned Signals
L3ECHO_CLK[2]
{L3_DATA[32:47], L3DP[4:5]}
L3_CLK[1]
{L3DATA[48:63], L3DP[6:7]}
L3_ECHO_CLK[3]
SRAM 0
SA[17:0]
B3
GND
G
GND
LBO
GND
B1
B2
CQ
CQ
NC
CK
CQ
NC
D[18:35]
CK
GVDD/2 1
D[0:17]
CQ
SRAM 1
SA[17:0]
B3
B1
G
B2
GND
CQ
GND
LBO
GND
D[0:17]
CQ
NC
CK
CQ
NC
D[18:35]
CK
GVDD/2 1
CQ
Note:
1. Or as recommended by SRAM manufacturer for single-ended clocking.
Figure 9. Typical Source Synchronous 2-Mbyte L3 Cache DDR Interface
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
25
Electrical and Thermal Characteristics
Figure 10 shows the L3 bus timing diagrams for the MPC7455 interfaced to MSUG2 SRAMs.
Outputs
VM
L3_CLK[0,1]
VM
tL3CHOV
VM
VM
VM
tL3CHOZ
tL3CHOX
ADDR, L3CNTL
tL3CLDV
tL3CLDZ
tL3CHDV
L3DATA WRITE
tL3CHDX
tL3CLDX
VM = Midpoint Voltage (GVDD/2)
Note: tL3CHDV and tL3CLDV as drawn here will be negative numbers, that is, output valid time will be
time before the clock edge.
Inputs
L3_ECHO_CLK[0,1,2,3]
VM
VM
VM
tL3DVEL
VM
VM
tL3DXEL
tL3DVEH
L3 Data and Data
Parity Inputs
tL3DXEH
VM = Midpoint Voltage (GVDD/2)
Note: tL3DVEH and tL3DVEL as drawn here will be negative numbers, that is, input setup time will be
time after the clock edge.
Figure 10. L3 Bus Timing Diagrams for L3 Cache DDR SRAMs
5.2.4.2 L3 Bus AC Specifications for PB2 and Late Write SRAMs
When using PB2 or late write SRAMs at the L3 interface, the parts should be connected as shown in Figure 11.
These SRAMs are synchronous to the MPC7455; one L3_CLKn signal is output to each SRAM to latch address,
control, and write data. Read data is launched by the SRAM synchronous to the delayed L3_CLKn signal it received.
The MPC7455 needs a copy of that delayed clock which launched the SRAM read data to know when the returning
data will be valid. Therefore, L3_ECHO_CLK1 and L3_ECHO_CLK3 must be routed halfway to the SRAMs and
then returned to the MPC7455 inputs L3_ECHO_CLK0 and L3_ECHO_CLK2, respectively. Thus,
L3_ECHO_CLK0 and L3_ECHO_CLK2 are phase-aligned with the input clock received at the SRAMs. The
MPC7455 will latch the incoming data on the rising edge of L3_ECHO_CLK0 and L3_ECHO_CLK2.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
26
Freescale Semiconductor
Electrical and Thermal Characteristics
Table 13 provides the L3 bus interface AC timing specifications for the configuration shown in Figure 11, assuming
the timing relationships of Figure 12 and the loading of Figure 8.
Table 13. L3 Bus Interface AC Timing Specifications for PB2 and Late Write SRAMs
At recommended operating conditions. See Table 4.
All Speed Grades 6
Parameter
Symbol L3OH0 = 0, L3OH1 = 0 L3OH0 = 0, L3OH1 =1 L3OH0 = 1, L3OH1 = 0 L3OH0 = 1, L3OH1 = 1 Unit Notes
Min
Max
Min
Max
Min
Max
Min
Max
L3_CLK rise
and fall time
tL3CR,
tL3CF
—
1.0
—
1.0
—
1.0
—
1.0
ns
1, 5
Setup times:
Data and
parity
tL3DVEH
1.5
—
1.5
—
1.5
—
1.5
—
ns
2, 5
Input hold
times: Data
and parity
tL3DXEH
—
0.5
—
0.5
—
0.5
—
0.5
ns
2, 5
Valid times:
Data and
parity
tL3CHDV
—
tL3_CLK/4
+ 1.00
—
tL3_CLK/4
+ 0.80
—
tL3_CLK/4
+ 0.60
—
tL3_CLK/4
+ 0.40
ns
3, 4, 5
Valid times: All tL3CHOV
other outputs
—
tL3_CLK/4
+ 1.00
—
tL3_CLK/4
+ 0.80
—
tL3_CLK/4
+ 0.60
—
tL3_CLK/4
+ 0.40
ns
4
tL3CHDX tL3_CLK/4
– 0.40
—
tL3_CLK/4
– 0.60
—
tL3_CLK/4
– 0.80
—
tL3_CLK/4
– 1.00
—
ns
3, 4, 5
tL3CHOX tL3_CLK/4
Output hold
– 0.40
times: All other
outputs
—
tL3_CLK/4
– 0.60
—
tL3_CLK/4
– 0.80
—
tL3_CLK/4
– 1.00
—
ns
4, 5
2.0
—
2.0
—
2.0
—
2.0
ns
5
Output hold
times: Data
and parity
L3_CLK to
high
impedance:
Data and
parity
tL3CHDZ
—
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
27
Electrical and Thermal Characteristics
Table 13. L3 Bus Interface AC Timing Specifications for PB2 and Late Write SRAMs (continued)
At recommended operating conditions. See Table 4.
All Speed Grades 6
Parameter
Symbol L3OH0 = 0, L3OH1 = 0 L3OH0 = 0, L3OH1 =1 L3OH0 = 1, L3OH1 = 0 L3OH0 = 1, L3OH1 = 1 Unit Notes
tL3CHOZ
L3_CLK to
high
impedance: All
other outputs
Min
Max
Min
Max
Min
Max
Min
Max
—
2.0
—
2.0
—
2.0
—
2.0
ns
5
Notes:
1. Rise and fall times for the L3_CLK output are measured from 20% to 80% of GVDD.
2. All input specifications are measured from the midpoint of the signal in question to the midpoint voltage of the rising edge of
the input L3_ECHO_CLK n (see Figure 10). Input timings are measured at the pins.
3. All output specifications are measured from the midpoint voltage of the rising edge of L3_CLKn to the midpoint of the signal
in question. The output timings are measured at the pins. All output timings assume a purely resistive 50-Ω load (see
Figure 10).
4. tL3_CLK/4 is one-fourth the period of L3_CLK n. This parameter indicates that the specified output signal is actually launched
by an internal clock delayed in phase by 90°. Therefore, there is a frequency component to the output valid and output hold
times such that the specified output signal will be valid for approximately one L3_CLK period starting three-fourths of a clock
prior to the edge on which the SRAM will sample it and ending one-fourth of a clock period after the edge it will be sampled.
5. Timing behavior and characterization are currently being evaluated.
6. These configuration bits allow the AC timing of the L3 interface to be altered via software. L3OH0 = L2CR[12],
L30H1 = L3CR[12]. Revisions of the MPC7455 not described by this document may implement these bits differently. See
Section 11.1, “Part Numbers Fully Addressed by This Document,” and Section 11.2, “Part Numbers Not Fully Addressed by
This Document,” for more information on which devices are addressed by this document.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
28
Freescale Semiconductor
Electrical and Thermal Characteristics
Figure 11 shows the typical connection diagram for the MPC7455 interfaced to PB2 SRAMs, such as the Freescale
MCM63R737, or late write SRAMs, such as the Freescale MCM63R836A.
MPC7455
L3_ADDR[16:0]
L3_CNTL[0]
L3_CNTL[1]
Denotes
Receive (SRAM
to MPC7455)
Aligned Signals
L3_ECHO_CLK[0]
{L3_DATA[0:15], L3_DP[0:1]}
L3_CLK[0]
{L3_DATA[16:31], L3_DP[2:3]}
Denotes
Transmit
(MPC7455 to
SRAM)
Aligned Signals
SRAM 0
SA[16:0]
SS
SW
DQ[0:17]
ZZ
GND
K
G
GND
DQ[18:36]
K
GVDD/2 1
L3_ECHO_CLK[1]
SRAM 1
SA[16:0]
SS
L3_ECHO_CLK[2]
{L3_DATA[32:47], L3_DP[4:5]}
L3_CLK[1]
{L3_DATA[48:63], L3_DP[6:7]}
SW
ZZ
GND
K
G
GND
DQ[18:36]
K
GV DD/2 1
DQ[0:17]
L3_ECHO_CLK[3]
Note:
1. Or as recommended by SRAM manufacturer for single-ended clocking.
Figure 11. Typical Synchronous 1-MByte L3 Cache Late Write or PB2 Interface
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
29
Electrical and Thermal Characteristics
Figure 12 shows the L3 bus timing diagrams for the MPC7455 interfaced to PB2 or late write SRAMs.
Outputs
L3_CLK[0,1]
L3_ECHO_CLK[1,3]
VM
VM
tL3CHOX
tL3CHOV
ADDR, L3_CNTL
tL3CHOZ
tL3CHDV
tL3CHDX
L3DATA WRITE
tL3CHDZ
Inputs
L3_ECHO_CLK[0,2]
VM
tL3DVEH
tL3DXEH
Parity Inputs
L3 Data and Data
VM = Midpoint Voltage (GVDD/2)
Figure 12. L3 Bus Timing Diagrams for Late Write or PB2 SRAMs
5.2.5
IEEE 1149.1 AC Timing Specifications
Table 14 provides the IEEE 1149.1 (JTAG) AC timing specifications as defined in Figure 14 through Figure 17.
Table 14. JTAG AC Timing Specifications (Independent of SYSCLK) 1
At recommended operating conditions. See Table 4.
Parameter
Symbol
Min
Max
Unit
TCK frequency of operation
fTCLK
0
33.3
MHz
TCK cycle time
t TCLK
30
—
ns
TCK clock pulse width measured at 1.4 V
tJHJL
15
—
ns
tJR and tJF
0
2
ns
TRST assert time
tTRST
25
—
ns
2
Input setup times:
Boundary-scan data
TMS, TDI
ns
3
tDVJH
tIVJH
4
0
—
—
Input hold times:
Boundary-scan data
TMS, TDI
ns
3
tDXJH
tIXJH
20
25
—
—
TCK rise and fall times
Notes
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
30
Freescale Semiconductor
Electrical and Thermal Characteristics
Table 14. JTAG AC Timing Specifications (Independent of SYSCLK) 1 (continued)
At recommended operating conditions. See Table 4.
Parameter
Symbol
Min
Max
Valid times:
Boundary-scan data
TDO
tJLDV
tJLOV
4
4
20
25
Output hold times:
Boundary-scan data
TDO
tJLDX
tJLOX
TBD
TBD
TBD
TBD
TCK to output high impedance:
Boundary-scan data
TDO
tJLDZ
tJLOZ
3
3
19
9
Unit
Notes
ns
4
ns
4
ns
4, 5
Notes:
1. All outputs are measured from the midpoint voltage of the falling/rising edge of TCLK to the midpoint of the signal
in question. The output timings are measured at the pins. All output timings assume a purely resistive 50-Ω load
(see Figure 13). Time-of-flight delays must be added for trace lengths, vias, and connectors in the system.
2. TRST is an asynchronous level sensitive signal. The setup time is for test purposes only.
3. Non-JTAG signal input timing with respect to TCK.
4. Non-JTAG signal output timing with respect to TCK.
5. Guaranteed by design and characterization.
Figure 13 provides the AC test load for TDO and the boundary-scan outputs of the MPC7455.
Z0 = 50 Ω
Output
RL = 50 Ω
OVDD/2
Figure 13. Alternate AC Test Load for the JTAG Interface
Figure 14 provides the JTAG clock input timing diagram.
TCLK
VM
VM
VM
tJHJL
tJR
tJF
tTCLK
VM = Midpoint Voltage (OVDD/2)
Figure 14. JTAG Clock Input Timing Diagram
Figure 15 provides the TRST timing diagram.
TRST
VM
VM
tTRST
VM = Midpoint Voltage (OVDD/2)
Figure 15. TRST Timing Diagram
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
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Electrical and Thermal Characteristics
Figure 16 provides the boundary-scan timing diagram.
TCK
VM
VM
tDVJH
Boundary
Data Inputs
tDXJH
Input
Data Valid
tJLDV
tJLDX
Boundary
Data Outputs
Output Data Valid
tJLDZ
Boundary
Data Outputs
Output Data Valid
VM = Midpoint Voltage (OVDD /2)
Figure 16. Boundary-Scan Timing Diagram
Figure 17 provides the test access port timing diagram.
TCK
VM
VM
tIVJH
tIXJH
Input
Data Valid
TDI, TMS
tJLOV
tJLOX
Output Data Valid
TDO
tJLOZ
TDO
Output Data Valid
VM = Midpoint Voltage (OVDD/2)
Figure 17. Test Access Port Timing Diagram
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
32
Freescale Semiconductor
Pin Assignments
6
Pin Assignments
Figure 18 (in Part A) shows the pinout of the MPC7445, 360 CBGA package as viewed from the top surface. Part B
shows the side profile of the CBGA package to indicate the direction of the top surface view.
Part A
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
T
U
V
W
Not to Scale
Part B
Substrate Assembly
Encapsulant
View
Die
Figure 18. Pinout of the MPC7445, 360 CBGA Package as Viewed from the Top Surface
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
33
Pin Assignments
Figure 19 (in Part A) shows the pinout of the MPC7455, 483 CBGA package as viewed from the top surface. Part B
shows the side profile of the CBGA package to indicate the direction of the top surface view.
Part A
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20 21 22
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
T
U
V
W
Y
AA
AB
Not to Scale
Part B
Substrate Assembly
Encapsulant
View
Die
Figure 19. Pinout of the MPC7455, 483 CBGA Package as Viewed from the Top Surface
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
34
Freescale Semiconductor
Pinout Listings
7
Pinout Listings
Table 15 provides the pinout listing for the MPC7445, 360 CBGA package. Table 16 provides the pinout listing for
the MPC7455, 483 CBGA package.
NOTE
This pinout is not compatible with the MPC750, MPC7400, or MPC7410, 360
BGA package.
Table 15. Pinout Listing for the MPC7445, 360 CBGA Package
Pin Number
Active
I/O
I/F Select 1
Notes
A[0:35]
E11, H1, C11, G3, F10, L2, D11, D1, C10,
G2, D12, L3, G4, T2, F4, V1, J4, R2, K5,
W2, J2, K4, N4, J3, M5, P5, N3, T1, V2,
U1, N5, W1, B12, C4, G10, B11
High
I/O
BVSEL
11
AACK
R1
Low
Input
BVSEL
AP[0:4]
C1, E3, H6, F5, G7
High
I/O
BVSEL
ARTRY
N2
Low
I/O
BVSEL
AV DD
A8
—
Input
N/A
BG
M1
Low
Input
BVSEL
BMODE0
G9
Low
Input
BVSEL
5
BMODE1
F8
Low
Input
BVSEL
6
BR
D2
Low
Output
BVSEL
BVSEL
B7
High
Input
BVSEL
1, 7
CI
J1
Low
Output
BVSEL
8
CKSTP_IN
A3
Low
Input
BVSEL
CKSTP_OUT
B1
Low
Output
BVSEL
CLK_OUT
H2
High
Output
BVSEL
D[0:63]
R15, W15, T14, V16, W16, T15, U15,
P14, V13, W13, T13, P13, U14, W14,
R12, T12, W12, V12, N11, N10, R11, U11,
W11, T11, R10, N9, P10, U10, R9, W10,
U9, V9, W5, U6, T5, U5, W7, R6, P7, V6,
P17, R19, V18, R18, V19, T19, U19, W19,
U18, W17, W18, T16, T18, T17, W3, V17,
U4, U8, U7, R7, P6, R8, W8, T8
High
I/O
BVSEL
DBG
M2
Low
Input
BVSEL
DP[0:7]
T3, W4, T4, W9, M6, V3, N8, W6
High
I/O
BVSEL
DRDY
R3
Low
Output
BVSEL
4
DTI[0:3]
G1, K1, P1, N1
High
Input
BVSEL
13
EXT_QUAL
A11
High
Input
BVSEL
9
Signal Name
8
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
35
Pinout Listings
Table 15. Pinout Listing for the MPC7445, 360 CBGA Package (continued)
Signal Name
Pin Number
Active
I/O
I/F Select 1
Low
I/O
BVSEL
—
—
N/A
Notes
GBL
E2
GND
B5, C3, D6, D13, E17, F3, G17, H4, H7,
H9, H11, H13, J6, J8, J10, J12, K7, K3,
K9, K11, K13, L6, L8, L10, L12, M4, M7,
M9, M11, M13, N7, P3, P9, P12, R5, R14,
R17, T7, T10, U3, U13, U17, V5, V8, V11,
V15
HIT
B2
Low
Output
BVSEL
HRESET
D8
Low
Input
BVSEL
INT
D4
Low
Input
BVSEL
L1_TSTCLK
G8
High
Input
BVSEL
9
L2_TSTCLK
B3
High
Input
BVSEL
12
No Connect
A6, A13, A14, A15, A16, A17, A18, A19,
B13, B14, B15, B16, B17, B18, B19, C13,
C14, C15, C16, C17, C18, C19, D14, D15,
D16, D17, D18, D19, E12, E13, E14, E15,
E16, E19, F12, F13, F14, F15, F16, F17,
F18, F19, G11, G12, G13, G14, G15,
G16, G19, H14, H15, H16, H17, H18,
H19, J14, J15, J16, J17, J18, J19, K15,
K16, K17, K18, K19, L14, L15, L16, L17,
L18, L19, M14, M15, M16, M17, M18,
M19, N12, N13, N14, N15, N16, N17,
N18, N19, P15, P16, P18, P19
—
—
—
3
LSSD_MODE
E8
Low
Input
BVSEL
2, 7
MCP
C9
Low
Input
BVSEL
OV DD
B4, C2, C12, D5, E18, F2, G18, H3, J5,
K2, L5, M3, N6, P2, P8, P11, R4, R13,
R16, T6, T9, U2, U12, U16, V4, V7, V10,
V14
—
—
N/A
PLL_CFG[0:4]
B8, C8, C7, D7, A7
High
Input
BVSEL
PMON_IN
D9
Low
Input
BVSEL
PMON_OUT
A9
Low
Output
BVSEL
QACK
G5
Low
Input
BVSEL
QREQ
P4
Low
Output
BVSEL
SHD[0:1]
E4, H5
Low
I/O
BVSEL
SMI
F9
Low
Input
BVSEL
SRESET
A2
Low
Input
BVSEL
SYSCLK
A10
—
Input
BVSEL
TA
K6
Low
Input
BVSEL
4
10
8
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
36
Freescale Semiconductor
Pinout Listings
Table 15. Pinout Listing for the MPC7445, 360 CBGA Package (continued)
Signal Name
Pin Number
Active
I/O
I/F Select 1
Notes
TBEN
E1
High
Input
BVSEL
TBST
F11
Low
Output
BVSEL
TCK
C6
High
Input
BVSEL
TDI
B9
High
Input
BVSEL
TDO
A4
High
Output
BVSEL
TEA
L1
Low
Input
BVSEL
TEST[0:3]
A12, B6, B10, E10
—
Input
BVSEL
2
TEST[4]
D10
—
Input
BVSEL
9
TMS
F1
High
Input
BVSEL
7
TRST
A5
Low
Input
BVSEL
7, 14
TS
L4
Low
I/O
BVSEL
8
TSIZ[0:2]
G6, F7, E7
High
Output
BVSEL
TT[0:4]
E5, E6, F6, E9, C5
High
I/O
BVSEL
WT
D3
Low
Output
BVSEL
VDD
H8, H10, H12, J7, J9, J11, J13, K8, K10,
K12, K14, L7, L9, L11, L13, M8, M10, M12
—
—
N/A
7
8
Notes:
1. OV DD supplies power to the processor bus, JTAG, and all control signals; and VDD supplies power to the processor
core and the PLL (after filtering to become AVDD). To program the I/O voltage, connect BVSEL to either GND
(selects 1.8 V) or to HRESET (selects 2.5 V). If used, the pulldown resistor should be less than 250 Ω. For actual
recommended value of Vin or supply voltages see Table 4.
2. These input signals are for factory use only and must be pulled up to OVDD for normal machine operation.
3. These signals are for factory use only and must be left unconnected for normal machine operation.
4. Ignored in 60x bus mode.
5. This signal selects between MPX bus mode (asserted) and 60x bus mode (negated) and will be sampled at
HRESET going high.
6. This signal must be negated during reset, by pull-up to OVDD or negation by ¬HRESET (inverse of HRESET), to
ensure proper operation.
7. Internal pull-up on die.
8. These pins require weak pull-up resistors (for example, 4.7 kΩ ) to maintain the control signals in the negated state
after they have been actively negated and released by the MPC7445 and other bus masters.
9. These input signals are for factory use only and must be pulled down to GND for normal machine operation.
10.This pin can externally cause a performance monitor event. Counting of the event is enabled via software.
11.Unused address pins must be pulled down to GND.
12.This test signal is recommended to be tied to HRESET; however, other configurations will not adversely affect
performance.
13.These signals must be pulled down to GND if unused, or if the MPC7445 is in 60x bus mode.
14.This signal must be asserted during reset, by pull-down to GND or assertion by HRESET, to ensure proper
operation.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
37
Pinout Listings
Table 16. Pinout Listing for the MPC7455, 483 CBGA Package
Pin Number
Active
I/O
I/F Select 1
Notes
A[0:35]
E10, N4, E8, N5, C8, R2, A7, M2, A6, M1,
A10, U2, N2, P8, M8, W4, N6, U6, R5, Y4, P1,
P4, R6, M7, N7, AA3, U4, W2, W1, W3, V4,
AA1, D10, J4, G10, D9
High
I/O
BVSEL
11
AACK
U1
Low
Input
BVSEL
AP[0:4]
L5, L6, J1, H2, G5
High
I/O
BVSEL
ARTRY
T2
Low
I/O
BVSEL
AV DD
B2
—
Input
N/A
BG
R3
Low
Input
BVSEL
BMODE0
C6
Low
Input
BVSEL
5
BMODE1
C4
Low
Input
BVSEL
6
BR
K1
Low
Output
BVSEL
BVSEL
G6
High
Input
N/A
3, 7
CI
R1
Low
Output
BVSEL
8
CKSTP_IN
F3
Low
Input
BVSEL
CKSTP_OUT
K6
Low
Output
BVSEL
CLK_OUT
N1
High
Output
BVSEL
D[0:63]
AB15, T14, R14, AB13, V14, U14, AB14,
W16, AA11, Y11, U12, W13, Y14, U13, T12,
W12, AB12, R12, AA13, AB11, Y12, V11, T11,
R11, W10, T10, W11, V10, R10, U10, AA10,
U9, V7, T8, AB4, Y6, AB7, AA6, Y8, AA7, W8,
AB10, AA16, AB16, AB17, Y18, AB18, Y16,
AA18, W14, R13, W15, AA14, V16, W6,
AA12, V6, AB9, AB6, R7, R9, AA9, AB8, W9
High
I/O
BVSEL
DBG
V1
Low
Input
BVSEL
DP[0:7]
AA2, AB3, AB2, AA8, R8, W5, U8, AB5
High
I/O
BVSEL
DRDY
T6
Low
Output
BVSEL
4
DTI[0:3]
P2, T5, U3, P6
High
Input
BVSEL
13
EXT_QUAL
B9
High
Input
BVSEL
9
GBL
M4
Low
I/O
BVSEL
Signal Name
8
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
38
Freescale Semiconductor
Pinout Listings
Table 16. Pinout Listing for the MPC7455, 483 CBGA Package (continued)
Pin Number
Active
I/O
I/F Select 1
GND
A22, B1, B5, B12, B14, B16, B18, B20, C3,
C9, C21, D7, D13, D15, D17, D19, E2, E5,
E21, F10, F12, F14, F16, F19, G4, G7, G17,
G21, H13, H15, H19, H5, J3, J10, J12, J14,
J17, J21, K5, K9, K11, K13, K15, K19, L10,
L12, L14, L17, L21, M3, M6, M9, M11, M13,
M19, N10, N12, N14, N17, N21, P3, P9, P11,
P13, P15, P19, R17, R21, T13, T15, T19, T4,
T7, T9, U17, U21, V2, V5, V8, V12, V15, V19,
W7, W17, W21, Y3, Y9, Y13, Y15, Y20, AA5,
AA17, AB1, AB22
—
—
N/A
GV DD
B13, B15, B17, B19, B21, D12, D14, D16,
D18, D21, E19, F13, F15, F17, F21, G19,
H12, H14, H17, H21, J19, K17, K21, L19,
M17, M21, N19, P17, P21, R15, R19, T17,
T21, U19, V17, V21, W19, Y21
—
—
N/A
15
HIT
K2
Low
Output
BVSEL
4
HRESET
A3
Low
Input
BVSEL
INT
J6
Low
Input
BVSEL
L1_TSTCLK
H4
High
Input
BVSEL
9
L2_TSTCLK
J2
High
Input
BVSEL
12
L3VSEL
A4
High
Input
N/A
3, 7
L3ADDR[17:0]
F20, J16, E22, H18, G20, F22, G22, H20,
K16, J18, H22, J20, J22, K18, K20, L16, K22,
L18
High
Output
L3VSEL
L3_CLK[0:1]
V22, C17
High
Output
L3VSEL
L3_CNTL[0:1]
L20, L22
Low
Output
L3VSEL
L3DATA[0:63]
AA19, AB20, U16, W18, AA20, AB21, AA21,
T16, W20, U18, Y22, R16, V20, W22, T18,
U20, N18, N20, N16, N22, M16, M18, M20,
M22, R18, T20, U22, T22, R20, P18, R22,
M15, G18, D22, E20, H16, C22, F18, D20,
B22, G16, A21, G15, E17, A20, C19, C18,
A19, A18, G14, E15, C16, A17, A16, C15,
G13, C14, A14, E13, C13, G12, A13, E12,
C12
High
I/O
L3VSEL
L3DP[0:7]
AB19, AA22, P22, P16, C20, E16, A15, A12
High
I/O
L3VSEL
L3_ECHO_CLK[0,2]
V18, E18
High
Input
L3VSEL
L3_ECHO_CLK[1,3]
P20, E14
HIgh
I/O
L3VSEL
LSSD_MODE
F6
Low
Input
BVSEL
MCP
B8
Low
Input
BVSEL
Signal Name
Notes
2, 7
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
39
Pinout Listings
Table 16. Pinout Listing for the MPC7455, 483 CBGA Package (continued)
Pin Number
Active
I/O
I/F Select 1
Notes
No Connect
A8, A11, B6, B11, C11, D11, D3, D5, E11, E7,
F2, F11, G11, G2, H11, H9, J8
—
—
N/A
16
OV DD
B3, C5, C7, C10, D2, E3, E9, F5, G3, G9, H7,
J5, K3, L7, M5, N3, P7, R4, T3, U5, U7, U11,
U15, V3, V9, V13, Y2, Y5, Y7, Y10, Y17, Y19,
AA4, AA15
—
—
N/A
PLL_CFG[0:4]
A2, F7, C2, D4, H8
High
Input
BVSEL
PMON_IN
E6
Low
Input
BVSEL
PMON_OUT
B4
Low
Output
BVSEL
QACK
K7
Low
Input
BVSEL
QREQ
Y1
Low
Output
BVSEL
SHD[0:1]
L4, L8
Low
I/O
BVSEL
SMI
G8
Low
Input
BVSEL
SRESET
G1
Low
Input
BVSEL
SYSCLK
D6
—
Input
BVSEL
TA
N8
Low
Input
BVSEL
TBEN
L3
High
Input
BVSEL
TBST
B7
Low
Output
BVSEL
TCK
J7
High
Input
BVSEL
TDI
E4
High
Input
BVSEL
TDO
H1
High
Output
BVSEL
TEA
T1
Low
Input
BVSEL
TEST[0:5]
B10, H6, H10, D8, F9, F8
—
Input
BVSEL
2
TEST[6]
A9
—
Input
BVSEL
9
TMS
K4
High
Input
BVSEL
7
TRST
C1
Low
Input
BVSEL
7, 14
TS
P5
Low
I/O
BVSEL
8
TSIZ[0:2]
L1,H3,D1
High
Output
BVSEL
TT[0:4]
F1, F4, K8, A5, E1
High
I/O
BVSEL
WT
L2
Low
Output
BVSEL
Signal Name
10
8
7
8
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
40
Freescale Semiconductor
Package Description
Table 16. Pinout Listing for the MPC7455, 483 CBGA Package (continued)
Pin Number
Active
I/O
I/F Select 1
J9, J11, J13, J15, K10, K12, K14, L9, L11,
L13, L15, M10, M12, M14, N9, N11, N13, N15,
P10, P12, P14
—
—
N/A
Signal Name
VDD
Notes
Notes:
1. OV DD supplies power to the processor bus, JTAG, and all control signals except the L3 cache controls (L3CTL[0:1]);
GV DD supplies power to the L3 cache interface (L3ADDR[0:17], L3DATA[0:63], L3DP[0:7], L3_ECHO_CLK[0:3],
and L3_CLK[0:1]) and the L3 control signals L3_CNTL[0:1]; and VDD supplies power to the processor core and the
PLL (after filtering to become AVDD). For actual recommended value of Vin or supply voltages, see Table 4.
2. These input signals are for factory use only and must be pulled up to OVDD for normal machine operation.
3. To program the processor interface I/O voltage, connect BVSEL to either GND (selects 1.8 V) or to HRESET (selects
2.5 V). To program the L3 interface, connect L3VSEL to either GND (selects 1.8 V) or to HRESET (selects 2.5 V)
or to HRESET (selects 1.5 V). If used, pulldown resistors should be less than 250 Ω.
4. Ignored in 60x bus mode.
5. This signal selects between MPX bus mode (asserted) and 60x bus mode (negated) and will be sampled at
HRESET going high.
6. This signal must be negated during reset, by pull-up to OVDD or negation by ¬HRESET (inverse of HRESET), to
ensure proper operation.
7. Internal pull-up on die.
8. These pins require weak pull-up resistors (for example, 4.7 kΩ) to maintain the control signals in the negated state
after they have been actively negated and released by the MPC7455 and other bus masters.
9. These input signals for factory use only and must be pulled down to GND for normal machine operation.
10.This pin can externally cause a performance monitor event. Counting of the event is enabled via software.
11.Unused address pins must be pulled down to GND.
12.This test signal is recommended to be tied to HRESET; however, other configurations will not adversely affect
performance.
13.These signals must be pulled down to GND if unused or if the MPC7455 is in 60x bus mode.
14.This signal must be asserted during reset, by pull-down to GND or assertion by HRESET, to ensure proper
operation.
15.Power must be supplied to GVDD, even when the L3 interface is disabled or unused.
16.These signals are for factory use only and must be left unconnected for normal machine operation.
8
Package Description
The following sections provide the package parameters and mechanical dimensions for the CBGA package.
8.1 Package Parameters for the MPC7445, 360 CBGA
The package parameters are as provided in the following list. The package type is 25 × 25 mm, 360-lead ceramic
ball grid array (CBGA).
Package outline
Interconnects
Pitch
Minimum module height
Maximum module height
Ball diameter
25 × 25 mm
360 (19 × 19 ball array – 1)
1.27 mm (50 mil)
2.72 mm
3.24 mm
0.89 mm (35 mil)
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
41
Package Description
8.2 Mechanical Dimensions for the MPC7445, 360 CBGA
Figure 20 provides the mechanical dimensions and bottom surface nomenclature for the MPC7445, 360 CBGA
package.
2X
0.2
D
Capacitor Region
B
D1
A1 CORNER
A
0.15 A
1
NOTES:
1. DIMENSIONING AND TOLERANCING
PER ASME Y14.5M, 1994.
2. DIMENSIONS IN MILLIMETERS.
3. TOP SIDE A1 CORNER INDEX IS A
METALIZED FEATURE WITH VARIOUS
SHAPES. BOTTOM SIDE A1 CORNER IS
DESIGNATED WITH A BALL MISSING
FROM THE ARRAY.
E3
E
E2
E1
Millimeters
2X
0.2
D2
C
DIM
MIN
MAX
A
2.72
3.20
A1
0.80
1.00
A2
1.10
1.30
A3
—
0.6
b
0.82
0.93
1 2 3 4 5 6 7 8 9 10 11 1213141516 17 18 19
W
V
U
T
R
P
N
M
L
K
J
H
G
F
E
D
C
B
A
e
360X
b
0.3 A B C
A3
A2
A1
A
D
25.00 BSC
D1
—
6.15
D2
12.15
12.45
e
1.27 BSC
E
25.00 BSC
E1
—
11.1
E2
7.45
—
E3
8.75
9.20
0.15 A
Figure 20. Mechanical Dimensions and Bottom Surface Nomenclature for the MPC7445,
360 CBGA Package
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
42
Freescale Semiconductor
Package Description
8.3 Substrate Capacitors for the MPC7445, 360 CBGA
Figure 21 shows the connectivity of the substrate capacitor pads for the MPC7445, 360 CBGA. All capacitors are
100 nF.
A1 Corner
1
C4-2
C5-2
C6-2
C4-1
C5-1
C6-1
C3-2
C2-2
C1-2
C3-1
C2-1
C1-1
Pad Number
Capacitor
-1
-2
C1
OVDD
GND
C2
VDD
GND
C3
OVDD
GND
C4
VDD
GND
C5
OVDD
GND
C6
VDD
GND
Figure 21. Substrate Bypass Capacitors for the MPC7445, 360 CBGA
8.4 Package Parameters for the MPC7455, 483 CBGA
The package parameters are as provided in the following list. The package type is 29 × 29 mm, 483-lead ceramic
ball grid array (CBGA).
Package outline
Interconnects
Pitch
Minimum module height
Maximum module height
Ball diameter
29 × 29 mm
483 (22 × 22 ball array – 1)
1.27 mm (50 mil)
—
3.22 mm
0.89 mm (35 mil)
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
43
Package Description
8.5 Mechanical Dimensions for the MPC7455, 483 CBGA
Figure 22 provides the mechanical dimensions and bottom surface nomenclature for the MPC7455, 483 CBGA
package.
2X
0.2
D
B
D1
D3
A1 CORNER
Capacitor Region
D2
1
A
0.15 A
NOTES:
1. DIMENSIONING AND TOLERANCING
PER ASME Y14.5M, 1994.
2. DIMENSIONS IN MILLIMETERS.
3. TOP SIDE A1 CORNER INDEX IS A
METALIZED FEATURE WITH VARIOUS
SHAPES. BOTTOM SIDE. A1 CORNER
IS DESIGNATED WITH A BALL
MISSING FROM THE ARRAY.
E3
E
E4
E1
E2
Millimeters
2X
0.2
D4
C
1 2 3 4 5 6 7 8 9 10 11 1213141516 171819 2021 22
AB
AA
Y
W
V
U
T
R
P
N
M
L
K
J
H
G
F
E
D
C
B
A
e
483X
b
0.3 A B C
0.15 A
A3
A2
A1
A
DIM
MIN
MAX
A
2.72
3.20
A1
0.80
1.00
A2
1.10
1.30
A3
--
0.60
b
0.82
0.93
D
29.00 BSC
D1
—
11.6
D2
8.94
—
D3
—
7.1
D4
12.15
12.45
e
1.27 BSC
E
29.00 BSC
E1
—
11.6
E2
8.94
—
E3
—
6.9
E4
8.75
9.20
Figure 22. Mechanical Dimensions and Bottom Surface Nomenclature for the MPC7455,
483 CBGA Package
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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Freescale Semiconductor
System Design Information
8.6 Substrate Capacitors for the MPC7455, 483 CBGA
Figure 23 shows the connectivity of the substrate capacitor pads for the MPC7455, 483 CBGA. All capacitors are
100 nF.
A1 Corner
1
Pad Number
C12-2
C3-1
C2-2
C2-1
C1-2
C11-1
C11-2
C6-2
C5-2
C3-2
C10-1
C9-2
C10-2
C8-2
Capacitor
C9-1
C4-2
C4-1
C5-1
C6-1
C7-2
C8-1
C12-1
C7-1
-1
-2
C1
OVDD
GND
C2
VDD
GND
C3
OVDD
GND
C4
OVDD
GND
C5
VDD
GND
C6
OVDD
GND
C7
AVDD
GND
C8
OVDD
GND
C9
GVDD
GND
C10
GVDD
GND
C11
VDD
GND
C12
GVDD
GND
C1-1
Figure 23. Substrate Bypass Capacitors for the MPC7455, 483 CBGA
9
System Design Information
This section provides system and thermal design recommendations for successful application of the MPC7455.
9.1 PLL Configuration
The MPC7455 PLL is configured by the PLL_CFG[0:4] signals. For a given SYSCLK (bus) frequency, the PLL
configuration signals set the internal CPU and VCO frequency of operation. The PLL configuration for the
MPC7455 is shown in Table 17 for a set of example frequencies. In this example, shaded cells represent settings
that, for a given SYSCLK frequency, result in core and/or VCO frequencies that do not comply with the 1-GHz
column in Table 8. Note that these configurations were different in devices prior to Rev F; see Section 11.2, “Part
Numbers Not Fully Addressed by This Document,” for more information regarding documentation of prior
revisions.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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System Design Information
Table 17. MPC7455 Microprocessor PLL Configuration Example for 1.0 GHz Parts
Example Bus-to-Core Frequency in MHz (VCO Frequency in MHz)
PLL_
CFG[0:4]
Bus (SYSCLK) Frequency
Bus-toCore
Multiplier
Core-toVCO
Multiplier
01000
2x
2x
10000
3x
2x
10100
4x
2x
10110
5x
2x
500
(1000)
667
(1333)
10010
5.5x
2x
550
(1100)
733
(1466)
11010
6x
2x
600
(1200)
800
(1600)
01010
6.5x
2x
540
(1080)
650
(1300)
866
(1730)
00100
7x
2x
525
(1050)
580
(1160)
700
(1400)
931
(1862)
00010
7.5x
2x
500
(1000)
563
(1125)
623
(1245)
750
(1500)
1000
(2000)
11000
8x
2x
533
(1066)
600
(1200)
664
(1328)
800
(1600)
01100
8.5x
2x
566
(1132)
638
(1276)
706
(1412)
850
(1700)
01111
9x
2x
600
(1200)
675
(1350)
747
(1494)
900
(1800)
01110
9.5x
2x
633
(1266)
712
(1524)
789
(1578)
950
(1900)
10101
10x
2x
500
(1000)
667
(1333)
750
(1500)
830
(1660)
1000
(2000)
10001
10.5x
2x
525
(1050)
700
(1400)
938
(1876)
872
(1744)
10011
11x
2x
550
(1100)
733
(1466)
825
(1650)
913
(1826)
00000
11.5x
2x
575
(1150)
766
(532)
863
(1726)
955
(1910)
10111
12x
2x
600
(1200)
800
(1600)
900
(1800)
996
(1992)
33.3
MHz
50
MHz
66.6
MHz
75
MHz
83
MHz
100
MHz
133
MHz
532
(1064)
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
46
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System Design Information
Table 17. MPC7455 Microprocessor PLL Configuration Example for 1.0 GHz Parts (continued)
Example Bus-to-Core Frequency in MHz (VCO Frequency in MHz)
PLL_
CFG[0:4]
Bus-toCore
Multiplier
Core-toVCO
Multiplier
11111
12.5x
01011
Bus (SYSCLK) Frequency
33.3
MHz
50
MHz
66.6
MHz
75
MHz
2x
600
(1200)
833
(1666)
938
(1876)
13x
2x
650
(1300)
865
(1730)
975
(1950)
11100
13.5x
2x
675
(1350)
900
(1800)
11001
14x
2x
700
(1400)
933
(1866)
00011
15x
2x
500
(1000)
750
(1500)
1000
(2000)
11011
16x
2x
533
(1066)
800
(1600)
00001
17x
2x
566
(1132)
850
(1900)
00101
18x
2x
600
(1200)
900
(1800)
00111
20x
2x
667
(1334)
1000
(2000)
01001
21x
2x
700
(1400)
01101
24x
2x
800
(1600)
11101
28x
2x
933
(1866)
83
MHz
100
MHz
00110
PLL bypass
PLL off, SYSCLK clocks core circuitry directly
11110
PLL off
PLL off, no core clocking occurs
133
MHz
Notes:
1. PLL_CFG[0:4] settings not listed are reserved.
2. The sample bus-to-core frequencies shown are for reference only. Some PLL configurations may select bus, core,
or VCO frequencies which are not useful, not supported, or not tested for by the MPC7455; see Section 5.2.1,
“Clock AC Specifications,” for valid SYSCLK, core, and VCO frequencies.
3. In PLL-bypass mode, the SYSCLK input signal clocks the internal processor directly and the PLL is disabled.
However, the bus interface unit requires a 2x clock to function. Therefore, an additional signal, EXT_QUAL, must
be driven at one-half the frequency of SYSCLK and offset in phase to meet the required input setup tIVKH and hold
time tIXKH (see Table 9). The result will be that the processor bus frequency will be one-half SYSCLK while the
internal processor is clocked at SYSCLK frequency. This mode is intended for factory use and emulator tool use
only.
Note: The AC timing specifications given in this document do not apply in PLL-bypass mode.
4. In PLL-off mode, no clocking occurs inside the MPC7455 regardless of the SYSCLK input.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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47
System Design Information
The MPC7455 generates the clock for the external L3 synchronous data SRAMs by dividing the core clock
frequency of the MPC7455. The core-to-L3 frequency divisor for the L3 PLL is selected through the L3_CLK bits
of the L3CR register. Generally, the divisor must be chosen according to the frequency supported by the external
RAMs, the frequency of the MPC7455 core, and timing analysis of the circuit board routing. Table 18 shows various
example L3 clock frequencies that can be obtained for a given set of core frequencies.
Table 18. Sample Core-to-L3 Frequencies
Core Frequency
(MHz)
÷2
÷2.5
÷3
÷3.5
÷4
÷5
÷6
500
250
200
167
143
125
100
83
533
266
213
178
152
133
107
89
550
275
220
183
157
138
110
92
600
300
240
200
171
150
120
100
6502
325
260
217
186
163
130
108
6662
333
266
222
190
167
133
111
7002
350
280
233
200
175
140
117
7332
367
293
244
209
183
147
122
8002
400
320
266
230
200
160
133
8672
433
347
289
248
217
173
145
9332
467
373
311
266
233
187
156
10002
500
400
333
285
250
200
166
Notes:
1. The core and L3 frequencies are for reference only. Note that maximum L3 frequency is design dependent. Some
examples may represent core or L3 frequencies which are not useful, not supported, or not tested for the MPC7455;
see Section 5.2.3, “L3 Clock AC Specifications,” for valid L3_CLK frequencies and for more information regarding
the maximum L3 frequency. Shaded cells do not comply with Table 10.
2. These core frequencies are not supported by all speed grades; see Table 8.
9.2 PLL Power Supply Filtering
The AV DD power signal is provided on the MPC7455 to provide power to the clock generation PLL. To ensure
stability of the internal clock, the power supplied to the AVDD input signal should be filtered of any noise in the 500
kHz to 10 MHz resonant frequency range of the PLL. A circuit similar to the one shown in Figure 24 using surface
mount capacitors with minimum effective series inductance (ESL) is recommended.
The circuit should be placed as close as possible to the AVDD pin to minimize noise coupled from nearby circuits.
It is often possible to route directly from the capacitors to the AVDD pin, which is on the periphery of the 360 CBGA
footprint and very close to the periphery of the 483 CBGA footprint, without the inductance of vias.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
48
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System Design Information
10 Ω
VDD
AVDD
2.2 µF
2.2 µF
Low ESL Surface Mount Capacitors
GND
Figure 24. PLL Power Supply Filter Circuit
9.3 Decoupling Recommendations
Due to the MPC7455 dynamic power management feature, large address and data buses, and high operating
frequencies, the MPC7455 can generate transient power surges and high frequency noise in its power supply,
especially while driving large capacitive loads. This noise must be prevented from reaching other components in the
MPC7455 system, and the MPC7455 itself requires a clean, tightly regulated source of power. Therefore, it is
recommended that the system designer place at least one decoupling capacitor at each VDD, OVDD, and GVDD pin
of the MPC7455. It is also recommended that these decoupling capacitors receive their power from separate V DD,
OVDD/GVDD, and GND power planes in the PCB, utilizing short traces to minimize inductance.
These capacitors should have a value of 0.01 or 0.1 µF. Only ceramic surface mount technology (SMT) capacitors
should be used to minimize lead inductance, preferably 0508 or 0603 orientations where connections are made along
the length of the part. Consistent with the recommendations of Dr. Howard Johnson in High Speed Digital Design:
A Handbook of Black Magic (Prentice Hall, 1993) and contrary to previous recommendations for decoupling
Freescale microprocessors, multiple small capacitors of equal value are recommended over using multiple values of
capacitance.
In addition, it is recommended that there be several bulk storage capacitors distributed around the PCB, feeding the
VDD, GV DD, and OVDD planes, to enable quick recharging of the smaller chip capacitors. These bulk capacitors
should have a low equivalent series resistance (ESR) rating to ensure the quick response time necessary. They should
also be connected to the power and ground planes through two vias to minimize inductance. Suggested bulk
capacitors: 100–330 µF (AVX TPS tantalum or Sanyo OSCON).
9.4 Connection Recommendations
To ensure reliable operation, it is highly recommended to connect unused inputs to an appropriate signal level.
Unused active low inputs should be tied to OVDD. Unused active high inputs should be connected to GND. All NC
(no-connect) signals must remain unconnected.
Power and ground connections must be made to all external VDD, OVDD, GVDD, and GND pins in the MPC7455.
If the L3 interface is not used, GV DD should be connected to the OVDD power plane, and L3VSEL should be
connected to BVSEL.
9.5 Output Buffer DC Impedance
The MPC7455 processor bus and L3 I/O drivers are characterized over process, voltage, and temperature. To
measure Z0, an external resistor is connected from the chip pad to OVDD or GND. Then, the value of each resistor
is varied until the pad voltage is OVDD/2 (see Figure 25).
The output impedance is the average of two components, the resistances of the pull-up and pull-down devices. When
data is held low, SW2 is closed (SW1 is open), and RN is trimmed until the voltage at the pad equals OVDD/2. RN
then becomes the resistance of the pull-down devices. When data is held high, SW1 is closed (SW2 is open), and
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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49
System Design Information
RP is trimmed until the voltage at the pad equals OV DD/2. RP then becomes the resistance of the pull-up devices. RP
and RN are designed to be close to each other in value. Then, Z 0 = (RP + RN)/2.
OVDD
RN
SW2
Data
Pad
SW1
RP
OGND
Figure 25. Driver Impedance Measurement
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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System Design Information
Table 19 summarizes the signal impedance results. The impedance increases with junction temperature and is
relatively unaffected by bus voltage.
Table 19. Impedance Characteristics
VDD = 1.5 V, OVDD = 1.8 V ± 5%, Tj = 5°–85°C
Impedance
Z0
Processor Bus
L3 Bus
Unit
Typical
33–42
34–42
Ω
Maximum
31–51
32–44
Ω
9.6 Pull-Up/Pull-Down Resistor Requirements
The MPC7455 requires high-resistive (weak: 4.7-kΩ) pull-up resistors on several control pins of the bus interface
to maintain the control signals in the negated state after they have been actively negated and released by the
MPC7455 or other bus masters. These pins are: TS, ARTRY, SHDO, and SHD1.
Some pins designated as being for factory test must be pulled up to OVDD or down to GND to ensure proper device
operation. For the MPC7445, 360 BGA, the pins that must be pulled up to OVDD are: LSSD_MODE and TEST[0:3];
the pins that must be pulled down to GND are: L1_TSTCLK and TEST[4]. For the MPC7455, 483 BGA, the pins
that must be pulled up to OVDD are: LSSD_MODE and TEST[0:5]; the pins that must be pulled down are:
L1_TSTCLK and TEST[6]. The CKSTP_IN signal should likewise, be pulled up through a pull-up resistor (weak
or stronger: 4.7–1 kΩ) to prevent erroneous assertions of this signal
In addition, the MPC7455 has one open-drain style output that requires a pull-up resistor (weak or stronger:
4.7–1 kΩ) if it is used by the system. This pin is CKSTP_OUT.
If pull-down resistors are used to configure BVSEL or L3VSEL, the resistors should be less than 250 Ω (see
Table 16). Because PLL_CFG[0:4] must remain stable during normal operation, strong pull-up and pull-down
resistors (1 kΩ or less) are recommended to configure these signals in order to protect against erroneous switching
due to ground bounce, power supply noise or noise coupling.
During inactive periods on the bus, the address and transfer attributes may not be driven by any master and may,
therefore, float in the high-impedance state for relatively long periods of time. Because the MPC7455 must
continually monitor these signals for snooping, this float condition may cause excessive power draw by the input
receivers on the MPC7455 or by other receivers in the system. These signals can be pulled up through weak (10-kΩ)
pull-up resistors by the system, address bus driven mode enabled (see the MPC7450 RISC Microporcessor Family
Users’ Manual for more information on this mode), or they may be otherwise driven by the system during inactive
periods of the bus to avoid this additional power draw. Preliminary studies have shown the additional power draw
by the MPC7455 input receivers to be negligible and, in any event, none of these measures are necessary for proper
device operation. The snooped address and transfer attribute inputs are: A[0:35], AP[0:4], TT[0:4], CI, WT, and
GBL.
If extended addressing is not used, A[0:3] are unused and must be pulled low to GND through weak pull-down
resistors. If the MPC7455 is in 60x bus mode, DTI[0:3] must be pulled low to GND through weak pull-down
resistors.
The data bus input receivers are normally turned off when no read operation is in progress and, therefore, do not
require pull-up resistors on the bus. Other data bus receivers in the system, however, may require pull-ups, or that
those signals be otherwise driven by the system during inactive periods by the system. The data bus signals are:
D[0:63] and DP[0:7].
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
51
System Design Information
If address or data parity is not used by the system, and the respective parity checking is disabled through HID0, the
input receivers for those pins are disabled, and those pins do not require pull-up resistors and should be left
unconnected by the system. If all parity generation is disabled through HID0, then all parity checking should also
be disabled through HID0, and all parity pins may be left unconnected by the system.
The L3 interface does not normally require pull-up resistors.
9.7 JTAG Configuration Signals
Boundary-scan testing is enabled through the JTAG interface signals. The TRST signal is optional in the IEEE
1149.1 specification, but is provided on all processors that implement the PowerPC architecture. While it is possible
to force the TAP controller to the reset state using only the TCK and TMS signals, more reliable power-on reset
performance will be obtained if the TRST signal is asserted during power-on reset. Because the JTAG interface is
also used for accessing the common on-chip processor (COP) function, simply tying TRST to HRESET is not
practical.
The COP function of these processors allows a remote computer system (typically, a PC with dedicated hardware
and debugging software) to access and control the internal operations of the processor. The COP interface connects
primarily through the JTAG port of the processor, with some additional status monitoring signals. The COP port
requires the ability to independently assert HRESET or TRST in order to fully control the processor. If the target
system has independent reset sources, such as voltage monitors, watchdog timers, power supply failures, or
push-button switches, then the COP reset signals must be merged into these signals with logic.
The arrangement shown in Figure 26 allows the COP port to independently assert HRESET or TRST, while ensuring
that the target can drive HRESET as well. If the JTAG interface and COP header will not be used, TRST should be
tied to HRESET through a 0-Ω isolation resistor so that it is asserted when the system reset signal (HRESET) is
asserted, ensuring that the JTAG scan chain is initialized during power-on. While Freescale recommends that the
COP header be designed into the system as shown in Figure 26, if this is not possible, the isolation resistor will allow
future access to TRST in the case where a JTAG interface may need to be wired onto the system in debug situations.
The COP header shown in Figure 26 adds many benefits—breakpoints, watchpoints, register and memory
examination/modification, and other standard debugger features are possible through this interface—and can be as
inexpensive as an unpopulated footprint for a header to be added when needed.
The COP interface has a standard header for connection to the target system, based on the 0.025" square-post, 0.100"
centered header assembly (often called a Berg header). The connector typically has pin 14 removed as a connector
key.
There is no standardized way to number the COP header shown in Figure 26; consequently, many different pin
numbers have been observed from emulator vendors. Some are numbered top-to-bottom then left-to-right, while
others use left-to-right then top-to-bottom, while still others number the pins counter clockwise from pin 1 (as with
an IC). Regardless of the numbering, the signal placement recommended in Figure 26 is common to all known
emulators.
The QACK signal shown in Figure 26 is usually connected to the PCI bridge chip in a system and is an input to the
MPC7455 informing it that it can go into the quiescent state. Under normal operation this occurs during a low-power
mode selection. In order for COP to work, the MPC7455 must see this signal asserted (pulled down). While shown
on the COP header, not all emulator products drive this signal. If the product does not, a pull-down resistor can be
populated to assert this signal. Additionally, some emulator products implement open-drain type outputs and can
only drive QACK asserted; for these tools, a pull-up resistor can be implemented to ensure this signal is de-asserted
when it is not being driven by the tool. Note that the pull-up and pull-down resistors on the QACK signal are
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
52
Freescale Semiconductor
System Design Information
mutually exclusive and it is never necessary to populate both in a system. To preserve correct power-down operation,
QACK should be merged via logic so that it also can be driven by the PCI bridge.
From Target
Board Sources
(if any)
SRESET
SRESET
HRESET
HRESET
QACK
13
11
HRESET
10 kΩ
SRESET
10 kΩ
OVDD
OVDD
10 kΩ
OVDD
10 kΩ
OVDD
0Ω5
1
2
3
4
5
6
7
8
9
10
11
12
TRST
6
5
VDD_SENSE
15
10 kΩ
2 kΩ
1
OVDD
OVDD
CHKSTP_OUT
CHKSTP_OUT
10 kΩ
Key
14 2
KEY
10 kΩ
COP Connector
Physical Pin Out
COP Header
16
OVDD
OVDD
CHKSTP_IN
13 No Pin
15
TRST
4
CHKSTP_IN
8
TMS
9
1
3
TMS
TDO
TDO
TDI
TDI
TCK
7
2
TCK
QACK
10
NC
12
NC
QACK
2 kΩ 3
10 kΩ 4
OVDD
16
Notes:
1. RUN/STOP, normally found on pin 5 of the COP header, is not implemented on the MPC7455. Con
pin 5 of the COP header to OVDD with a 10-kΩ pull-up resistor.
2. Key location; pin 14 is not physically present on the COP header.
3. Component not populated. Populate only if debug tool does not drive QACK.
4. Populate only if debug tool uses an open-drain type output and does not actively de-assert QACK
5. If the JTAG interface is implemented, connect HRESET from the target source to TRST from the
header though an AND gate to TRST of the part. If the JTAG interface is not implemented, con
HRESET from the target source to TRST of the part through a 0-Ω isolation reisistor.
Figure 26. JTAG Interface Connection
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
53
System Design Information
9.8 Thermal Management Information
This section provides thermal management information for the ceramic ball grid array (CBGA) package for
air-cooled applications. Proper thermal control design is primarily dependent on the system-level design—the heat
sink, airflow, and thermal interface material. To reduce the die-junction temperature, heat sinks may be attached to
the package by several methods—spring clip to holes in the printed-circuit board or package, and mounting clip and
screw assembly (see Figure 27); however, due to the potential large mass of the heat sink, attachment through the
printed-circuit board is suggested. If a spring clip is used, the spring force should not exceed 10 pounds.
CBGA Package
Heat Sink
Heat Sink
Clip
Thermal Interface Material
Printed-Circuit Board
Figure 27. Package Exploded Cross-Sectional View with Several Heat Sink Options
The board designer can choose between several types of heat sinks to place on the MPC7455. There are several
commercially available heat sinks for the MPC7455 provided by the following vendors:
Aavid Thermalloy
80 Commercial St.
Concord, NH 03301
Internet: www.aavidthermalloy.com
603-224-9988
Alpha Novatech
473 Sapena Ct. #15
Santa Clara, CA 95054
Internet: www.alphanovatech.com
408-749-7601
International Electronic Research Corporation (IERC)
413 North Moss St.
Burbank, CA 91502
Internet: www.ctscorp.com
818-842-7277
Tyco Electronics
Chip Coolers™
P.O. Box 3668
Harrisburg, PA 17105-3668
Internet: www.chipcoolers.com
800-522-6752
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
54
Freescale Semiconductor
System Design Information
Wakefield Engineering
33 Bridge St.
Pelham, NH 03076
Internet: www.wakefield.com
603-635-5102
Ultimately, the final selection of an appropriate heat sink depends on many factors, such as thermal performance at
a given air velocity, spatial volume, mass, attachment method, assembly, and cost.
9.8.1 Internal Package Conduction Resistance
For the exposed-die packaging technology, shown in Table 3, the intrinsic conduction thermal resistance paths are
as follows:
•
•
The die junction-to-case (actually top-of-die since silicon die is exposed) thermal resistance
The die junction-to-ball thermal resistance
Figure 28 depicts the primary heat transfer path for a package with an attached heat sink mounted to a printed-circuit
board.
Radiation
External Resistance
Convection
Heat Sink
Thermal Interface Material
Die/Package
Die Junction
Package/Leads
Internal Resistance
Printed-Circuit Board
External Resistance
Radiation
Convection
(Note the internal versus external package resistance.)
Figure 28. C4 Package with Heat Sink Mounted to a Printed-Circuit Board
Heat generated on the active side of the chip is conducted through the silicon, then through the heat sink attach
material (or thermal interface material), and finally to the heat sink where it is removed by forced-air convection.
Because the silicon thermal resistance is quite small, for a first-order analysis, the temperature drop in the silicon
may be neglected. Thus, the thermal interface material and the heat sink conduction/convective thermal resistances
are the dominant terms.
9.8.2 Thermal Interface Materials
A thermal interface material is recommended at the package lid-to-heat sink interface to minimize the thermal
contact resistance. For those applications where the heat sink is attached by spring clip mechanism, Figure 29 shows
the thermal performance of three thin-sheet thermal-interface materials (silicone, graphite/oil, floroether oil), a bare
joint, and a joint with thermal grease as a function of contact pressure. As shown, the performance of these thermal
interface materials improves with increasing contact pressure. The use of thermal grease significantly reduces the
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
Freescale Semiconductor
55
System Design Information
interface thermal resistance. That is, the bare joint results in a thermal resistance approximately seven times greater
than the thermal grease joint.
Often, heat sinks are attached to the package by means of a spring clip to holes in the printed-circuit board (see
Figure 27). Therefore, the synthetic grease offers the best thermal performance, considering the low interface
pressure and is recommended due to the high power dissipation of the MPC7455. Of course, the selection of any
thermal interface material depends on many factors—thermal performance requirements, manufacturability, service
temperature, dielectric properties, cost, etc.
Silicone Sheet (0.006 in.)
Bare Joint
Floroether Oil Sheet (0.007 in.)
Graphite/Oil Sheet (0.005 in.)
Synthetic Grease
Specific Thermal Resistance (K-in.2/W)
2
1.5
1
0.5
0
0
10
20
30
40
50
60
70
80
Contact Pressure (psi)
Figure 29. Thermal Performance of Select Thermal Interface Material
The board designer can choose between several types of thermal interface. Heat sink adhesive materials should be
selected based on high conductivity, yet adequate mechanical strength to meet equipment shock/vibration
requirements. There are several commercially available thermal interfaces and adhesive materials provided by the
following vendors:
The Bergquist Company
18930 West 78th St.
Chanhassen, MN 55317
Internet: www.bergquistcompany.com
800-347-4572
Chomerics, Inc.
77 Dragon Ct.
Woburn, MA 01888-4014
Internet: www.chomerics.com
781-935-4850
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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System Design Information
Dow-Corning Corporation
Dow-Corning Electronic Materials
2200 W. Salzburg Rd.
Midland, MI 48686-0997
Internet: www.dow.com
800-248-2481
Shin-Etsu MicroSi, Inc.
10028 S. 51st St.
Phoenix, AZ 85044
Internet: www.microsi.com
888-642-7674
Thermagon Inc.
4707 Detroit Ave.
Cleveland, OH 44102
Internet: www.thermagon.com
888-246-9050
The following section provides a heat sink selection example using one of the commercially available heat sinks.
9.8.3 Heat Sink Selection Example
For preliminary heat sink sizing, the die-junction temperature can be expressed as follows:
Tj = Ta + Tr + (RθJC + Rθint + Rθsa) × Pd
where:
Tj is the die-junction temperature
Ta is the inlet cabinet ambient temperature
Tr is the air temperature rise within the computer cabinet
RθJC is the junction-to-case thermal resistance
Rθint is the adhesive or interface material thermal resistance
Rθsa is the heat sink base-to-ambient thermal resistance
Pd is the power dissipated by the device
During operation, the die-junction temperatures (Tj) should be maintained less than the value specified in Table 4.
The temperature of air cooling the component greatly depends on the ambient inlet air temperature and the air
temperature rise within the electronic cabinet. An electronic cabinet inlet-air temperature (Ta) may range from 30°
to 40°C. The air temperature rise within a cabinet (Tr) may be in the range of 5° to 10°C. The thermal resistance of
the thermal interface material (Rθint) is typically about 1.5°C/W. For example, assuming a Ta of 30°C, a Tr of 5°C,
a CBGA package RθJC = 0.1, and a typical power consumption (Pd) of 15.0 W, the following expression for Tj is
obtained:
Die-junction temperature:
Tj = 30°C + 5°C + (0.1°C/W + 1.5°C/W + Rθsa) × 15 W
For this example, a Rθsa value of 3.1°C/W or less is required to maintain the die-junction temperature below the
maximum value of Table 4.
Though the die junction-to-ambient and the heat sink-to-ambient thermal resistances are a common figure-of-merit
used for comparing the thermal performance of various microelectronic packaging technologies, one should
exercise caution when only using this metric in determining thermal management because no single parameter can
adequately describe three-dimensional heat flow. The final die-junction operating temperature is not only a function
of the component-level thermal resistance, but the system-level design and its operating conditions. In addition to
the component's power consumption, a number of factors affect the final operating die-junction
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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57
System Design Information
temperature—airflow, board population (local heat flux of adjacent components), heat sink efficiency, heat sink
attach, heat sink placement, next-level interconnect technology, system air temperature rise, altitude, etc.
Due to the complexity and the many variations of system-level boundary conditions for today's microelectronic
equipment, the combined effects of the heat transfer mechanisms (radiation, convection, and conduction) may vary
widely. For these reasons, we recommend using conjugate heat transfer models for the board, as well as system-level
designs.
For system thermal modeling, the MPC7445 and MPC7455 thermal model is shown in Figure 30. Four volumes will
be used to represent this device. Two of the volumes, solder ball, and air and substrate, are modeled using the
package outline size of the package. The other two, die, and bump and underfill, have the same size as the die.
Dimensions for these volumes for the MPC7445 and MPC7455 are given in Figure 20 and Figure 22, respectively.
The silicon die should be modeled 9.10 × 12.25 × 0.74 mm with the heat source applied as a uniform source at the
bottom of the volume. The bump and underfill layer is modeled as 9.10 × 12.25 × 0.069 mm (or as a collapsed
volume) with orthotropic material properties: 0.6 W/(m • K) in the xy-plane and 2 W/(m • K) in the direction of the
z-axis. The substrate volume is 25 × 25 × 1.2 mm (MPC7445) or 29 × 29 × 1.2 mm (MPC7455), and this volume
has 18 W/(m • K) isotropic conductivity. The solder ball and air layer is modeled with the same horizontal
dimensions as the substrate and is 0.9 mm thick. It can also be modeled as a collapsed volume using orthotropic
material properties: 0.034 W/(m • K) in the xy-plane direction and 3.8 W/(m • K) in the direction of the z-axis.
Die
z
Conductivity
Value
Bump and Underfill
Substrate
Unit
Solder and Air
Bump and Underfill
Side View of Model (Not to Scale)
kx
0.6
ky
0.6
kz
2
W/(m • K)
x
Substrate
Substrate
k
18
Solder Ball and Air
kx
0.034
ky
0.034
kz
3.8
Die
y
Top View of Model (Not to Scale)
Figure 30. Recommended Thermal Model of MPC7445 and MPC7455
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Document Revision History
10 Document Revision History
Table 20 provides a revision history for this hardware specification.
Table 20. Document Revision History
Rev. No.
Substantive Change(s)
0
Initial release.
1
Updated for Rev F devices; information specific to Rev C devices is now documented in a separate part
number specifications; see Section 11.2, “Part Numbers Not Fully Addressed by This Document,” for
more information.
Removed 600 and 800 MHz speed grades.
Increased leakage current specifications in Table 6 from 10 to 30 µA.
Changed core voltage to 1.3 V; all instances of VDD and AV DD updated.
Updated power consumption specifications in Table 7.
Reduced I/O power guidance in Table 7 from <20% to <5%.
Added footnote 1 to Figure 9 and Figure 11.
Removed CI and WT from Input Setup and Input Hold lists in Table 10; these are output-only signals.
Removed INT, HRESET, MCP, SRESET, and SMI from Input Setup and Input Hold lists in Table 10;
these are asynchronous inputs.
Added TT[0:3] to Input Setup, Input Hold, Output Valid, and Output Hold lists in Table 10; these were
mistakenly omitted in Rev 0.
Updated Table 13 and Table 14 to reflect new L3 AC timing in Rev F devices.
Corrected Note 10 in Table 16 and Table 17; this is an event pin, not an enable pin.
Corrected entries for L3_ECHO_CLK[1,3] in Table 17; these are I/O pins, not input-only.
Added Note 16 to Table 17; all No Connect pins must be left unconnected.
Changed name of PLL_EXT to PLL_CFG[4] and updated all instances.
Updated Table 18 to reflect PLL configuration settings for Rev F devices.
Added dimensions D2 and E3 to Figure 20.
Transposed dimensions D4 and E4 in Figure 21 (dimensions were reversed).
Revised Figure 24 and Section 9.7, “JTAG Configuration Signals.”
Revised format of Section 11.2, “Part Numbers Not Fully Addressed by This Document,” and added
Table 23 through Table 26.
Revised Section 9.8.3, “Heat Sink Selection Example,” and added additional thermal modeling
information, including Figure 28.
Changed maximum heat sink clip spring force in Section 9.8, “Thermal Management Information,” from
5.5 lbs to 10 lbs.
Changed substrate marking for MPC7445 in Figure 29; all MPC744x device substrates are marked
MPC7440.
Changed substrate marking for MPC7455 in Figure 29; all MPC745x device substrates are marked
MPC7450.
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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59
Ordering Information
Table 20. Document Revision History (continued)
Rev. No.
Substantive Change(s)
1.1
Removed reference to Note 4 for DTI signals in Table 15 and Table 16: these signals are unused in 60x
bus mode and must be pulled down (see Note 13); they are not ignored.
Improved precision of die and package dimensions in Figure 20 and Figure 21.
2
Corrected entries in Table 17 for 33 MHz and 50 MHz bus frequencies with multipliers of 24x and higher.
Corrected typographical errors in heatsink selection example in Section 9.8.3, “Heat Sink Selection
Example.”
Removed erroneous instances of PLL_EXT signal name and changed remaining instances of
PLL_CFG[0:3] to PLL_CFG[0:4]. (These were artifacts from older revisions; see entry for Rev 1.0.)
Corrected erroneous instances (artifacts) mentioning 1.6 V core voltage. Core voltage for devices
completely covered by this revision (and revisions 1.x) of this document is 1.3 V.
Corrected errors in PLL multipliers in Table 17: 32x and 25x are not supported ratios, 3x and 4x are
supported, 10.5x and 12.5x PLL settings were incorrect.
Replaced notes at bottom of Table 17 (erroneously missing in revisions 1.x).
Updated coplanarity specifications in Figure 20 and Figure 21 from 0.2 mm to 0.15 mm.
3
Added Revision G (Rev 3.4) devices to specifications.
Added new PowerPC trademarking information.
4
Added substrate capacitor information in Section 8.3, “Substrate Capacitors for the MPC7445, 360
CBGA,” and Section 8.6, “Substrate Capacitors for the MPC7455, 483 CBGA.”
Clarified maximum and typical L3 clock frequency in Section 5.2.3, “L3 Clock AC Specifications”; typical
L3 frequency now stated as 250 MHz based on changes to L3 AC timing.
Significantly changed L3 AC timing in Table 12 and Table 13. These changes reflect both updates
based on latest characterization and error corrections (effects of non-zero L3OH values were incorrectly
documented in earlier revisions of this document).
Clarified address bus pull-up resistor recommendations in Section 9.6, “Pull-Up/Pull-Down Resistor
Requirements.”
Added pull-up/pull-down recommendations for CKSTP_IN and PLL_CFG[0:4] to Section 9.6,
“Pull-Up/Pull-Down Resistor Requirements.”
Modified Table 9, Figure 5, and Figure 6 to more accurately show when the mode select inputs
(BMODE[0:1], L3VSEL, BVSEL) are sampled and AC timing requirements.
Figure 20 and Figure 22: Updated/corrected dimensions in mechanical drawings.
4.1
Document tempate update.
11 Ordering Information
Ordering information for the parts fully covered by this specification document is provided in Section 11.1, “Part
Numbers Fully Addressed by This Document.” Note that the individual part numbers correspond to a maximum
processor core frequency. For available frequencies, contact your local Freescale sales office. In addition to the
processor frequency, the part numbering scheme also includes an application modifier which may specify special
application conditions. Each part number also contains a revision level code which refers to the die mask revision
number. Section 11.2, “Part Numbers Not Fully Addressed by This Document,” lists the part numbers which do not
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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Ordering Information
fully conform to the specifications of this document. These special part numbers require an additional document
called a part number specification.
11.1 Part Numbers Fully Addressed by This Document
Table 21 provides the Freescale part numbering nomenclature for the MPC7455.
Table 21. Part Numbering Nomenclature
xx
74x5
x
RX
nnnn
x
x
Product
Code
Part
Identifier
Process
Descriptor
Package
Processor
Frequency 1
Application
Modifier
Revision Level
XC 2
7455
7445
A
RX = CBGA
MC
733
867
933
1000
L: 1.3 V ± 50 mV
0 to 105°C
F: 3.3; PVR = 8001 0303
G: 3.4; PVR = 8001 0304
Notes:
1. Processor core frequencies supported by parts addressed by this specification only. Parts addressed by part
number specifications may support other maximum core frequencies.
2. The X prefix in a Freescale part number designates a “Pilot Production Prototype” as defined by Freescale SOP
3-13. These are from a limited production volume of prototypes manufactured, tested, and Q.A. inspected on a
qualified technology to simulate normal production. These parts have only preliminary reliability and
characterization data. Before pilot production prototypes may be shipped, written authorization from the customer
must be on file in the applicable sales office acknowledging the qualification status and the fact that product changes
may still occur while shipping pilot production prototypes.
11.2 Part Numbers Not Fully Addressed by This Document
Parts with application modifiers or revision levels not fully addressed in this specification document are described
in separate part number specifications which supplement and supersede this document; see Table 22 through
Table 25.
Table 22. Part Numbers Addressed by XPC74x5RXnnnLC Series Part Number Specification (Document
Order No. MPC7455RXLCPNS)
XPC
74x5
RX
nnn
L
C
Product
Code
Part
Identifier
Package
Processor
Frequency
Application Modifier
Revision Level
XPC
7455
7445
PPC
RX = CBGA
600
733
800
867
933
L: 1.6 V ± 50 mV
0 to 105°C
C: 2.1; PVR = 8001 0201
1000
MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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61
Ordering Information
Table 23. Part Numbers Addressed by XPC74x5RXnnnNx Series Part Number Specification (Document
Order No. MPC7455RXNXPNS)
XPC
74x5
RX
nnn
N
C
Product
Code
Part
Identifier
Package
Processor
Frequency
Application Modifier
Revision Level
XPC
7455
7445
RX = CBGA
600
733
800
N: 1.3 V ± 50 mV
0 to 105°C
C: 2.1; PVR = 8001 0201
Table 24. Part Numbers Addressed by XPC74x5RXnnnPx Series Part Number Specification (Document
Order No. MPC7455RXPXPNS)
XPC
7455
RX
nnn
P
C
Product
Code
Part
Identifier
Package
Processor
Frequency
Application Modifier
Revision Level
XPC
7455
RX = CBGA
933
1000
P: 1.85 V ± 50 mV
0 to 65°C
C: 2.1; PVR = 8001 0201
Table 25. Part Numbers Addressed by XPC74x5RXnnnSx Series Part Number Specification (Document
Order No. MPC7455RXSXPNS)
XPC
7455
RX
nnnn
S
C
Product
Code
Part
Identifier
Package
Processor
Frequency
Application Modifier
Revision Level
XPC
7455
RX = CBGA
1000
S: 1.85 V ± 50 mV
0 to 75°C
C: 2.1; PVR = 8001 0201
11.3 Part Marking
Parts are marked as the example shown in Figure 31.
MC7445A
RX1000LG
MMMMMM
ATWLYYWWA
7440
BGA
Notes:
MMMMMM is the 6-digit mask number.
ATWLYYWWA is the traceability code.
MC7455A
RX1000LG
MMMMMM
ATWLYYWWA
7450
BGA
Figure 31. Part Marking for BGA Device
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Ordering Information
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MPC7455 RISC Microprocessor Hardware Specifications, Rev. 4.1
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