Z90251 Datasheet, PDF (74/97 Pages) Zilog, Inc. – eZVision 200 Television Controllers with OSD

Z90255 ROM and Z90251 OTP
32 KB Television Controller with OSD
66
Bit/
Field
Bit
Position
R/W Value Description
Reserved
7, 6, 5, 4, 3 R
W
Return 0
No Effect
CAPint_r
2
R
0 No Rising Edge is Captured
1 Rising Edge is Captured
W
0 No Effect
1 Reset Flag
CAPint_f
1
R
0 No Falling Edge is Captured
1 Falling Edge is Captured
W
0 No Effect
1 Reset Flag
Tout_CAP
0
R
0 No Time-out of the Capture Timer
1 Time-out of the Capture Timer
W
0 No Effect
1 Reset Flag
During the interrupt service routine, software must read the contents of Timer
Control Register 0. Then it checks which bit is set to 1, indicating the type of edge
which generated the interrupt.
Table 51 Timer Control Register 1 02h: Bank C (TCR1)
Bit
7
6
5
R/W
Reset
R/W R/W R/W
x
1
0
Note: R = Read W = Write X = Indeterminate
4
R/W
0
3
R/W
0
2
R/W
0
1
R/W
0
0
R/W
0
Bit/
Field
Reserved
CAP Halt
CAP Edge
Bit
Position
7
6
5, 4
R/W Value Description
R
Return 0
W
No Effect
R/W
0 Capture Timer Running
1 Capture Timer Halted
R/W
00 No capture
01 Capture on Rising Edge Only
10 Capture on Falling Edge Only
11 Capture on Both Edges
PS001301-0800