MB90580 Datasheet, PDF (269/395 Pages) Fujitsu Component Limited. – 16-BIT MICROCONTROLLER

18.3 Regiaters and Register Details
18.3.2 PWC data buffer register (PWCR)
PWC Data Buffer Register (Upper Byte)
Address : 000057_H
Read/write
Initial value
15
14
(R/W) (R/W)
(X) (X)
13
(R/W)
(X)
12
(R/W)
(X)
11
(R/W)
(X)
10
(R/W)
(X)
9
(R/W)
(X)
8
Bit number
(R/W)
(X)
PWCR
(HIGH)
PWC Data Buffer Register (Lower Byte)
7
6
Address : 000056_H
Read/write
Initial value
(R/W) (R/W)
(X) (X)
5
(R/W)
(X)
4
(R/W)
(X)
3
(R/W)
(X)
2
(R/W)
(X)
1
(R/W)
(X)
0
(R/W)
(X)
Bit number
PWCR
(LOW)
(1) In timer mode
In reload timer operation mode (bit 3 S/C of PWCSR = "1"), this register stores the reload value. In
this case, the register is readable and writable.
In single-shot timer operation mode (bit 3 S/C of PWCSR = "0"), accessing this register directly
accesses the up-count timer. Although both reading and writing are allowed in this mode, only write
to the register when the timer is halted. The register can be read at any time to read the current
timer value.
(2) In pulse width count mode ♦ Read-only ♦
In continuous count mode (bit 3 S/C of PWCSR = "1"), this register acts as a buffer register to store
the previous count result. In this case, the register is read-only and writing does not change the
register value.
In single-shot count mode (bit 3 S/C of PWCSR = "0"), accessing this register directly accesses the
up-count timer. The register is read-only in this mode also and writing does not change the register
value. The register can be read at any time to read the current timer value. After the count ends, the
register stores the count result.
Note: Always use word transfer instructions to access this register.
After a reset: Initialized to "0000_H".
MB90580 Series
Chapter 18: Pulse Width Counter (PWC) Timer 249