ZEN2044F Zenic, ZEN2044F Datasheet - Page 13

• Manufacturer Part Number: ZEN2044F
• Description: 33MHz Up/down Counter
• Manufacturer: Zenic

www.DataSheet4U.com
5-2. System mode set command
5-3. Command register format(common to Mode 0 and Mode 1)
the Mode 1 select command at first because the Mode 0 is the default setting at reset.
value and controling action of Z phase input.
This is the command word to select system mode. If you use the conter in Mode 1, you need to write
(1) Mode 0[default]
(2) Mode 1
This is the command word for selecting register, selecting byte, latching counter, loading preloaded
CPU bus is 8 bit in the
byte or low byte) when the CPU accesses
and latch) and the up/down counter.
"every time" can be selected.
counter.
EXTA
EXTB
register format in detail.
BS1,BS0(Byte Select)
RS1,RS0(Register Select)
LT(Latch)
ZE1, ZE0(Z phase input control)
LD(Load)
Note 1)
Note 2)
The registers(preload, reference and latch) and the up/down counter have 24 bit length but the
RS1 and RS0 specify the register to be accessed from among the three registers(preload, reference
This bit is used to store the value of the up/down counter into the latch register.
ZE1 and ZE0 control the way of clearing the counter by Z phase input. One of "ignoring", "once" or
This bit is used to transmit the data which is stored in the preload register to the up/down
Do not execute Load and Latch operations at once.
When Load or Latch command is executed, the external pins, LT and LD , must be fixed at "1" .
D7
1
1
n
n
is set as a comparator output (EQA ) and EXTB
is set as an output. Both EXTA
D6
0
0
Table 7 Field format of command register(common to Mode 0 and Mode 1)
D5
0
0
D4
Table 6 Format of system mode set command
1
1
ZEN2044F.
LD
D7
D3
0
0
ZE1
D6
D2
0
0
The BS1 and BS0 determine the target byte(high byte, middle
ZE0
D1
D5
0
0
n
ZEN2044F.
- 13 -
and EXTB
D0
n
0
1
LT
D4
HeX
90
91
RS1
D3
n
Mode 0 select[default]
Mode 1 select
can be programed. Please refer to Mode1
n
RS0
D2
is set as a universal input U.
BS1
D1
Operation
BS0
D0
(
Z2044G00 ZENIC INC.
ZEN2044F
)