CDC3205G-C Micronas, CDC3205G-C Datasheet - Page 37

• Manufacturer Part Number: CDC3205G-C
• Description: Automotive Controller Family The Device is a Microcontroller For Use in Automotive Applications.the On-chip Cpu is an Arm Processor ARM7TDMI with 32-bit Data And Address Bus, Which Supports Thumb format Instructions.
• Manufacturer: Micronas

PRELIMINARY DATA SHEET
4. CPU and Clock System
4.1. ARM7TDMI
The CPU is an ARM7TDMI 32-bit RISC processor. This is a
member of the Advanced RISC Machines (ARM) family. The
ARM7TDMI is a 3 stage pipeline machine and supports a 4
Gbit address range. Besides the 32bit standard ARM instruc-
tion set the ARM7TDMI supports the 16bit Thumb instruction
set which allows a higher code density. It includes a 64bit
result multiplier and a JTAG interface with an embedded
debug module.
4.2. Operating Modes
To adapt to the large variety of CPU speed and current con-
sumption requirements, the device offers a number of oper-
ating modes:
– CPU-active modes, where the CPU is clocked at select-
Fig. 4–1:
Micronas
able speeds
FAST
Operating Modes State Diagram
™
CPUM=WAKE/STBY
CPUM=IDLE
CPUM=DEEP SLOW
CPUM=FAST
CPUM=SLOW
CPUM=FAST
CPUM=PLL
CPUM=FAST
CPU
with Ports
Power up
w/o Ports
Global
Global
Reset
Reset
<50ms (if 4/5MHz XTAL was off)
~0.5ms (if 4/5MHz XTAL stays on)
<50ms (if 4/5MHz XTAL was off)
~0.5ms (if 4/5MHz XTAL stays on)
128/f
128/f
~100 s
June 12, 2003; 6251-579-1PD
XTAL
XTAL
~ s
0
0
0
0
WAKE and
STANDBY
SLOW
SLOW
DEEP
IDLE
PLL
4.1.1. CPU States
The ARM7TDMI CPU allows operation in two states:
– ARM state: 32bit instructions
– Thumb state: 16bit instructions
After reset and exceptions, ARM state is active.
– Power saving modes, where the CPU is kept reset and
Fig. 4–1 shows how the various modes are accessed, in an
operating modes state diagram.
where only certain circuit portions are powered.
RESETQ, RTC, Wake Ports
RTC, Wake Ports
RESETQ
All reset sources
All reset sources
All reset sources
CDC 32xxG-C
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