1. HC08 ARCHITECTURE DETAILS

3. MC68HC08 Architecture Details
MC68HC08 Family
Nomenclature
Variations
Block Diagram
Pins
Memory Map

4. MC68HC08 Nomenclature MC 68 HC 7 08 XL 36 XX B/FU 1 2 3 4 5 6 7 8 9
1. Qualification Status: PC - no qual. XC - limited qual. MC - full qual.
2. Historic reasons. The 68 references Motorola’s first micro-processor, the MC All architectures are based of this device.
3. Speed/Power: H - High Speed C - 5.5V L - 2.0V
4. Memory type: Blank - ROM/ROMless EPROM/OTP EEPROM
5. CPU type: 08
6. Family and Member Indicators: X - Family L- Member
7. ROM Size: 36 KBytes ROM
8. Temperature range: Blank - (0 to 70C) C - (-40 to 85C) M - (-40 to 125C)
9. Package Type: B - SDIP FU - QFP

5. MC68HC08 Family Codes MC68HC708XL36FU
A Automotive N Gen. purpose (52/56 pin)
B Gen. purpose (16/20 pin) O -- avoided --
C Consumer P PC
D DSP Q Future gen. purpose/cpu ext.
E Gen. purpose (28/32 pin) R Future gen. purpose/cpu ext.
F Telephone S Smartcard
G Gen. purpose (40/42/44 pin) T Television
H Future gen. purpose/cpu ext. U -- avoided --
I -- avoided -- V VFD
J Future gen. purpose/cpu ext. W Future gen. purpose/cpu ext.
K Fuzzy (knowledge based) X Gen. purpose (56/64/68 pin)
L LCD Y Gen. purpose (80 pin)
M Motor control Z Gen. purpose ( pin)

6. MC68HC08 Member Codes MC68HC708XL36FU
A Multifunction timer parts M Other (A/D, etc)
B “ N “
C “ O “
D General timer parts P “
E “ Q “
F “ R “
G General timer + serial interface S Non-volatile memory + anything
H “ T “
I “ U “
J “ V “
K “ W “
L “ X “
Y “
Z “

7. New 68HC08 Introductions 68HC08AS20 68HC08LN56 ROM EPROM FLASH
68HC08AZ0
68HC08AZ16
68HC08AZ24
68HC08AZ32
68HC08AB0
68HC08AB16
68HC08AB24
68HC08AB32
CAN
Auto./Ind. M o t r C n l
Gen. Purp.
J1850
Consum.
Comm.
General
Purpose
68HC08MR16
68HC908AT32
68HC708XL36
68HC708AS48*
*-Prototyping
Qty. Only
68HC08XL36
68HC908XL36
68HC708LN56
68HC708MP16

8. MC68HC708XL36 Block Diagram INTERNAL BUS M68HC08 CPU PTA7 – PTA0 CPU
ARITHMETIC/LOGIC
REGISTERS
UNIT (ALU)
DIRECT MEMORY ACCESS
MODULE
PTB7 –
PTB0
CONTROL AND STATUS REGISTERS — 88 BYTES
BREAK
MODULE
USER EPROM — 36,864 BYTES
PTC7 –
PTC0
LOW-VOLTAGE INHIBIT
MODULE
USER RAM — 1024 BYTES
COMPUTER OPERATING PROPERLY
PTD7/KBD7 –
PTD0/KBD0
MONITOR ROM — 240 BYTES
MODULE
PTE7/TCH3
USER EPROM VECTOR SPACE — 32 BYTES
PTE6/TCH2
TIMER INTERFACE
MODULE
PTE5/TCH1
PTE4/TCH0
OSC1
CLOCK
GENERATOR
PTE3/TCLK
OSC2
MODULE
PTE2/TxD
CGMXFC
SERIAL COMMUNICATIONS INTERFACE
MODULE
PTE1/RxD
PTE0
PTF5
RST
SYSTEM INTEGRATION
PTF4
MODULE
PTF3/MISO
SERIAL PERIPHERAL INTERFACE
PTF2/MOSI
IRQ1 /V
IRQ
MODULE PP
PTF1/SPSCK
IRQ2
MODULE
PTF0/ SS
POWER-ON RESET
MODULE
PTG3 –
PTG0
(64-PIN PACKAGE ONLY) V SS V DD V
DDA
POWER
PTH3 –
PTH0
(64-PIN PACKAGE ONLY)
CGND/EVss

9. Overview of Pin Functions
BASIC SUPPORT PINS
VDD , VSS Power (+5V) and Ground
OSC1, OSC2 Crystal connection for on chip oscillator
RST External Reset, bidirectional
IRQ1/VPP, IRQ2 External Interrupt Request IRQ1 is also the EPROM programming power pin
CGND\EVSS Clock Ground
VDDA Clock Generation Module Power Supply
CGMXFC External Filter Capacitor for Clock Generation Module

10. MC68HC708XL36 MEMORY MAP I/O Registers (80 Bytes) $0000 – $004F
Port A - H
$0000
$000F 
Registers
RAM (1024) Bytes
$0050 – $044F
$0010
$0012 
Unused (27,056 Bytes)
$0450 – $6DFF
SPI
Registers
EPROM (36,864 Bytes
$6E00 – $FDFF
$0013
$0019 
SCI
Registers
SIM Break Status Register
$FE00
SIM Reset Status Register
$FE01
XIRQ
$001A
$001B
Reserved (1 Byte)
$FE02
Registers
SIM Break Flag Control Reg.
$FE03
$001C
$001E 
Reserved/Unimplemented
$FE04 – $FE06
CGM
Registers
EPROM Control Reg.
$FE07
$FFE0 - FFE1 IRQ2
Reserved (4 Bytes)
$FE08 – $FE0B
$FFE2 - FFE7 SCI
Mask Option Reg
$001F
Break Addres Reg. High
$FE0C
$FFE8 - FFEB SPI
Break Address Reg. Low
$FE0D
$0020
$0031 
Break Status/Control Reg.
$FE0E
$FFEC - FFF5 TIM
TIM
Registers
LVI Status/Control Reg.
$FE0F
Monitor ROM (240 Bytes)
$FE10 – $FEFF
$FFF6 - FFF7 DMA
$FFF8 - FFF9 PLL
Unused (192 Bytes)
$FF00 – $FFBF
$0032
$004E 
DMA
Registers
$FFFA - FFFB IRQ1
Reserved (32 Bytes)
$FFC0 – $FFDF
$FFFC - FFFD SWI
$FFE0
$FFFF 
Vectors (32 Bytes)
$FFFE - FFFF Reset
Unused
$004F
COP Control Reg.