Pwc Data Buffer Register (Pwcr0 To Pwcr2) - Fujitsu F2MC-16LX Hardware Manual

CHAPTER 14 PWC TIMER

14.2.2 PWC Data Buffer Register (PWCR0 to PWCR2)

This section describes the configuration and functions of the PWC data buffer register
(PWCR0 to 2).
I PWC data buffer register (PWCR0 to PWCR 2)
Figure 14.2-3 "Bit configuration of the PWC data buffer register (PWCR0 to 2)" shows the bit
configuration of the PWC data buffer register (PWCR0 to PWCR2).
Figure 14.2-3 Bit configuration of the PWC data buffer register (PWCR0 to 2)
000079
H
00007D D15
H
000081
H (R/W) (R/W) (R/W) (R/W) (R/W) (R/W) (R/W) (R/W)
000078
H
00007C
H
000080
H
(R/W) (R/W) ((R/W))(R/W) (R/W) (R/W) ((R/W))(R/W)
The function of the PWC data buffer register (PWCR0 to 2) depends on whether the timer mode
is selected (by setting the PWCSR register bits 2 to 0 (MOD2 to 0)) or the pulse width set mode
is selected.
❍ Timer mode (reading/writing allowed)
In a reload timer operation (PWCSR bit 3:S/C = 1), the PWC data buffer register operates as a
reload register to store reload data. In this case, both reading and writing are allowed.
In one-shot timer operation mode (PWCSR bit 3:S/C = 0), the PWC data buffer register is used
to directly access the up-count timer. In this case, both reading or writing are allowed, though
writing can only be performed when the timer is stopped. Reading is available at any time,
enabling the counter value to be read during counting.
❍ Pulse width measurement mode (Only reading allowed)
In repeated measurement mode (PWCSR bit 3: S/C = 1), the PWC data buffer register operates
as a buffer register to store the results of measurement.
In this case, only reading is allowed. Write operations do not change the value of the register.
In one-shot mode (PWCSR bit 3: S/C = 0), the PWC data buffer register is used to directly
access the up-count timer.
In this case, only reading is allowed. Write operations do not change the value of the register.
Reading is available at any time, enabling the counter value to be read during counting. After
the measurement ends, the PWC data buffer register stores the measurement result.
Note:
This register can only be accessed only via word transfer instructions. At reset, the register is
initialized to 00
282
15 14 13 12
D14 D13 D12
(0) (0) (0) (0)
7 6 5 4
D7 D6 D5 D4
(0) (0) (0) (0)
.
B
11 10 9 8
D11 D10 D9 D8
(0) (0) (0) (0)
3 2 1 0
D3 D2 D1 D0
(0) (0) (0) (0)
PWCR
PWC data buffer register
Reading/writing
Initial value
PWCR
PWC data buffer register
Reading/writing
Initial value