Renesas H8 Series - Register Descriptions

Section 9 Timers
Rev. 7.00 Mar 10, 2005 page 303 of 652
REJ09B0042-0700
9.6.2 Register Descriptions
Timer Control/Status Register W (TCSRW)
Bit
Initial value
Read/Write
7
B6WI
1
R
6
TCWE
0
(R/W)
*1
5
B4WI
1
R
4
TCSRWE
0
(R/W)
*1
3
B2WI
1
R
0
WRST
0
(R/W)
*1
2
WDON
0/1
*2
(R/W)
*1
1
B0WI
1
R
Notes: 1. Write is enabled only under certain conditions, which are given in the descriptions
of the individual bits.
2. Initial value is 0 on H8/38024, H8/38024S, and H8/38024R Group; initial value
is 1 on H8/38124 Group.
TCSRW is an 8-bit read/write register that controls write access to TCW and TCSRW itself,
controls watchdog timer operations, and indicates operating status.
Bit 7—Bit 6 Write Disable (B6WI)
Bit 7 controls the writing of data to bit 6 in TCSRW.
Bit 7
B6WI Description
0 Bit 6 is write-enabled
1 Bit 6 is write-protected (initial value)
This bit is always read as 1. Data written to this bit is not stored.
Bit 6—Timer Counter W Write Enable (TCWE)
Bit 6 controls the writing of data to TCW.
Bit 6
TCWE Description
0 Data cannot be written to TCW (initial value)
1 Data can be written to TCW