TMP88CS38N データシートの表示（PDF） - Toshiba

部品番号

コンポーネント説明

メーカー

TMP88CS38N

CMOS 8-Bit Microcontroller

Toshiba 

TMP88CS38/CM38A/CP38A

(2) Machine cycle

Instruction execution and peripheral hardware operation are synchronized with the

main system clock. The minimum instruction execution unit is called a “machine cycle”.

There are a total of 15 different types of instructions for the TLCS-870/X series:

Ranging from 1-cycle instructions which require one machine cycle for execution to

15-cycle instructions which require 15 machine cycles for execution.

A machine cycle consists of 4 states (S0 to S3), and each state consists of one main

system clock.

1/fc

Main system clock

fm

State

S0

S1

S2

S3

S0

S1

S2

S3

Machine cycle

(0.25 μs at fc = 16 MHz)

1.4.3

Figure 1.4.6 Machine Cycle

Standby Controller

The standby controller starts and stops the switches the main system clock. These modes

are controlled by the system control registers (SYSCR1, SYSCR2).

Figure 1.4.7 shows the operating mode transition diagram and Figure 1.4.8 shows the

system control registers.

(1) Single-clock mode

In the single-clock mode, the machine cycle time is 4/fc [s] (0.25 μs at fc = 16 MHz).

1. NORMAL mode

In this mode, both the CPU core and on-chip peripherals operate using the

high-frequency clock.

2. IDLE mode

In this mode, the internal oscillation circuit remains active. The CPU and the

watchdog timer are halted; however, on-chip peripherals remain active (Operate

using the high-frequency clock). IDLE mode is started by setting IDLE bit in the

system control register 2 (SYSCR2), and IDLE1 mode is released to NORMAL

mode by an interrupt request from on-chip peripherals or external interrupt

inputs. When IMF (Interrupt master enable flag) is “1” (Interrupt enable), the

execution will resume upon acceptance of the interrupt, and the operation will

return to normal after the interrupt service is completed. When IMF is “0”

(Interrupt disable), the execution will resume with the instruction which follows

IDLE mode start instruction.

3. STOP mode

In this mode, the internal oscillation circuit is turned off, causing all system

operations to be halted. The internal status immediately prior to the halt is held

with the lowest power consumption during this mode.

STOP mode is started by setting STOP bit in the system control register 1

(SYSCR1), and STOP mode is released by an input (Either level-sensitive or

edge-sensitive can be programmably selected) to the STOP pin. After the warm-up

period is completed, the execution resumes with the next instruction which

follows the STOP mode start instruction.

88CS38-11

2007-09-12

Share Link: