s3c72m9 Samsung Semiconductor, Inc., s3c72m9 Datasheet - Page 6

• Manufacturer Part Number: s3c72m9
• Description: The S3c72m5/s3c72m7/s3c72m9 Single-chip Cmos Microcontroller Has Been Designed For High Performance Using Samsung S
• Manufacturer: Samsung Semiconductor, Inc.

PRODUCT OVERVIEW
S3C72M5/C72M7/C72M9/P72M9 (Preliminary Spec)
POWER DOWN
To reduce power consumption, there are two power-down modes: idle and stop. The IDLE instruction initiates idle
mode and the STOP instruction initiates stop mode.
In idle mode, only the CPU clock stops while peripherals and the oscillation source continue to operate normally.
Stop mode effects only the main system clock — a subsystem clock, if used, continues oscillating. In stop mode,
main system clock oscillation stops completely, halting all operations except for a few basic peripheral functions.
RESET or an interrupt can be used to terminate either idle or stop mode.
RESET
When a RESET signal occurs during normal operation or during power-down mode, the CPU enters idle mode when
the reset operation is initiated. When the standard oscillation stabilization interval (31.3 ms at 4.19 MHz) has
elapsed, normal CPU operation resumes.
I/O PORTS
The S3C72M5/C72M7/C72M9 has 13 I/O ports. Pin addresses for all I/O ports are mapped in bank 15 of the RAM.
There are 4 input pins and 47 configurable I/O pins for a total of 51 I/O pins. The contents of I/O port pin latches can
be read, written, or tested at the corresponding address using bit manipulation instructions.
TIMERS and TIMER/COUNTERS
The timer function has four main components: an 8-bit basic interval timer, an 8-bit timer/counter, a 16-bit
timer/counter and a watch timer. The 8-bit basic timer generates interrupt requests at precise intervals, based on the
selected clock frequency and has watch-dog timer function.
The programmable 8-bit and 16-bit timer/counters are used for external event counting, generation of arbitrary clock
frequencies for output, and dividing external clock signals. The 16-bit timer/counter is the source of the clock signal
that is required to drive the serial I/O interface and configurable as two 8-bit timer/counters.
The watch timer has an 8-bit watch timer mode register, a clock selector and a frequency divider circuit. Its functions
include real-time and watch-time measurement, clock generation for the LCD controller and frequency outputs for
buzzer sound.
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