Fujitsu FR81S User Manual
CHAPTER 19: BASE TIMER
4. Registers
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER
: BASE TIMER
FUJITSU SEMICONDUCTOR CONFIDENTIAL
24
4.2.2. 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 16/32-bit reload timer. The down counter counts down from the
value set to these registers.
Notes:
⋅
These registers must be accessed in 16-bit mode.
⋅
Set these registers after selecting a base timer function to the 16/32-bit reload timer (FMD2 to FMD0 =
011) using the FMD2 to FMD0 bits of the timer control register (BTxTMCR).
⋅
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 16/32-bit reload timer. The down counter counts down from
the value set to these registers.
The value set to these registers is loaded to the 16-bit down counter in the following cases:
⋅
When the 16/32-bit reload timer is started
⋅
When the down counter underflows
The following values are set to these registers when two channels of a 16-bit reload timer are cascaded and it
is used as the 32-bit reload timer.
⋅
Value of even-number channel cycle setting register (BTxPCSR) : Value of lower 16-bit
⋅
Value of the odd-number channel cycle setting register (BTxPCSR) : Value of upper 16-bit
For this reason, in the 32-bit timer mode, write values into these registers in the following order.
1. Odd-number channel base timer x cycle setting register (BTxPCSR)
2. Even-number channel base timer x cycle setting register (BTxPCSR)
MB91520 Series
MN705-00010-1v0-E
657