Pwc Control Status Register (Pwcsr) - Fujitsu F2MC-16LX MB90580 Series Hardware Manual

18.3 Regiaters and Register Details

18.3.1 PWC control status register (PWCSR)

PWC Control Status Register (Upper Byte)
Address : 000055
Read/write
Initial value
PWC Control Status Register (Lower Byte)
Address : 000054
Read/write
Initial value
The PWCSR is used to control the operation of the PWC timer and to read the PWC timer status.
[bit 15] STRT (Start) & [bit 14] STOP (Stop)
These bits start, restart, and stop the 16-bit up-count timer. Reading the bits returns the operating state
of the timer. The bit functions are as follows.
Function of STRT and STOP bits when they are written. (Operation control)
STRT
0
0
1
1
Meaning of the STRT and STOP bits when they are read. (Operating status indication)
STRT
0
1
After a reset: Initialized to 00
Readable and writable. Note that the meanings of the bits differ for reading and writing.
Always read as 11
Although bit manipulation instructions (such as the bit clear instruction) can be used to write to the
STRT and STOP bits to start and stop the timer, bit manipulation instructions cannot be used to read
the operating status (as these always indicate that the timer is operating).
244 Chapter 18: Pulse Width Counter (PWC) Timer
15 14
STRT STOP EDIR
H
(R/W) (R/W)
(0) (0)
7 6
CSK1
CSK0 PIS1
H
(R/W) (R/W) (R/W)
(0) (0)
STOP
0 No function. Has no effect on operation.
1 Starts or restarts the timer (count enable). Note: The clear bit instruction can
be used.
0 Forcibly halts the operation of the timer (count disable). Note: The clear bit
instruction can be used.
1 No function. Has no effect on operation.
STOP
0 Timer is halted (not started or count ended). (Initial value)
1 Timer is counting (count in progress).
.
B
by read-modify-write instructions regardless of the actual values.
B
13 12 11
EDIE OVIR OVIE
(R) (R/W) (R/W) (R/W)
(0) (0) (0)
5 4 3
PIS0 S/C
MOD2
(R/W) (R/W) (R/W)
(0) (0) (0)
Operation Control Function
Operating Status Indication
10 9 8
PWCSR
ERR POUT
(HIGH)
(R) (R/W)
(0) (0) (0)
2 1 0
MOD1 MOD0 PWCSR
(LOW)
(R/W) (R/W)
(0) (0) (0)
MB90580 Series
Bit number
Bit number