Fujitsu FR81S User Manual
CHAPTER 19: BASE TIMER
4. Registers
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER
: BASE TIMER
FUJITSU SEMICONDUCTOR CONFIDENTIAL
28
4.3.2. Cycle Setting Registers 0, 1 : BTxPCSR (Base Timer
0/1 Pulse Counter Start Register)
The bit configuration of cycle setting registers 0, 1 (BTxPCSR) is shown below.
These registers with a buffer set the cycle for the 16-bit PWM timer. The 16-bit down counter counts down
from the value set to these registers. When the counter value matches the value set to these registers, the level
of the output signal (TOUT) is inverted.
Notes:
⋅
These registers must be accessed in 16-bit mode.
⋅
Set these registers after selecting a base timer function to the 16-bit PWM timer using the FMD2 to
FMD0 bits of the timer control register (BTxTMCR).
⋅
Be sure to rewrite the duty setting register (BTxPDUT) when these registers are rewritten.
⋅
Do not set a value smaller than the value set to the duty setting register (BTxPDUT).
⋅
These registers will also be initialized when reset mode is set (writing of BTxTMCR:FMD = 000).
BTxPCSR : Address Base_addr + 08
H
(Access: Half-word)
bit15
bit14
- - -
bit2
bit1
bit0
D[15:0]
Initial value
0
0
- - -
0
0
0
Attribute R/W
R/W
- - -
R/W
R/W
R/W
[bit15 to bit0] D[15:0] (Data) : Data bits
These registers with a buffer set the cycle for the 16-bit PWM timer. The 16-bit down counter counts down
from the value set to these registers. When the counter value matches the value set to these registers, the level
of the output signal (TOUT) is inverted.
These registers have a buffer and thus can be rewritten during counting. The value set to these registers is
loaded to the 16-bit down counter in the following cases:
⋅
When the 16-bit PWM timer is activated
⋅
When the down counter underflows
When the same value is set to these registers and the base timer x duty setting register (BTxPDUT), the level
of the output signal (TOUT) can be fixed. The output signal level is as follows according to the setting of the
OSEL bit of the base timer x timer control register (BTxTMCR):
⋅
OSEL=0: "H" level
⋅
OSEL=1: "L" level
MB91520 Series
MN705-00010-1v0-E
661