Toshiba TLCS-900/H1 Series Manual page 20

The clock operating modes are as follows: (a) single clock mode (X1, X2 pins only), (b) dual
clock mode (X1, X2, XT1 and XT2 pins) and (c) triple clock mode (X1, X2, XT1 and XT2 pins and
PLL).
Figure 3.3.1 shows a transition figure.
IDLE2 mode
(I/O operate)
IDLE1 mode
(Operate only oscillator)
IDLE2 mode
(I/O operate)
IDLE1 mode
(Operate only oscillator)
IDLE2 mode
(I/O operate)
IDLE1 mode
(Operate only oscillator)
IDLE2 mode
(I/O operate)
IDLE1 mode
(Operate only oscillator)
IDLE2 mode
(I/O operate)
IDLE1 mode
(Operate oscillator and PLL)
Note 1: It is not possible to control PLL in SLOW mode when shifting from SLOW mode to NORMAL mode with use of PLL.
(PLL start up/stop/change write to PLLCR0<PLLON>, PLLCR1<FCSEL> register)
Note 2: When shifting from NORMAL mode with use of PLL to NORMAL mode, execute the following setting in the same order.
1) Change CPU clock (PLLCR0<FCSEL> ← "0")
2) Stop PLL circuit (PLLCR1<PLLON> ← "0")
Note 3: It is not possible to shift from NORMAL mode with use of PLL to STOP mode directly.
NORMAL mode should be set once before shifting to STOP mode. (Sstop the high-frequency oscillator after stopping
PLL.)
The clock frequency input from the X1 and X2 pins is called fc and the clock frequency input from the XT1 and XT2 pins is called
fs. The clock frequency selected by SYSCR1<SYSCK> is called the clock f
clock of f , and one cycle of f
FPH
Instruction
Interrupt
Instruction
(f OSCH /gear value/2)
Interrupt
(a) Single clock mode transition figure
Instruction
Interrupt
Instruction
(f OSCH /gear value/2)
Interrupt
Instruction
Instruction
Interrupt
Instruction
Interrupt
(b) Dual clock mode transition figure
Instruction
Interrupt
Instruction
(f OSCH /gear value/2)
Interrupt
Instruction
Instruction
(Stops all circuits)
Note
Instruction
Interrupt
NORMAL mode
(4 × f OSCH /gear
Instruction
value/2)
Using PLL
Interrupt
(c) Triple clock mode transition figure
Figure 3.3.1 System Clock Block Diagram
is defined as one state.
SYS
Reset
(f /32)
OSCH
Release reset
Instruction
NORMAL mode
Interrupt
Reset
(f /32)
OSCH
Release reset
Instruction
mode
NORMAL
Interrupt
Interrupt
Instruction
SLOW mode
Interrupt
(fs/2)
Reset
(f /32)
OSCH
Release reset
mode
NORMAL
Interrupt
Instruction
STOP mode
Interrupt
Instruction
Instruction
SLOW mode
(fs/2)
Note
. The system clock f
FPH
92CH21-18
TMP92CH21
STOP mode
(Stops all circuits)
STOP mode
(Stops all circuits)
STOP mode
(Stops all circuits)
Instruction
IDLE2 mode
(I/O operate)
Interrupt
IDLE1 mode
Instruction
(Operate only oscillator)
Interrupt
is defined as the divided
SYS
2009-06-19