DatasheetQ Logo
Electronic component search and free download site. Transistors,MosFET ,Diode,Integrated circuits

HT9480(1998) データシートの表示(PDF) - Holtek Semiconductor

部品番号
コンポーネント説明
メーカー
HT9480
(Rev.:1998)
Holtek
Holtek Semiconductor Holtek
HT9480 Datasheet PDF : 57 Pages
First Prev 21 22 23 24 25 26 27 28 29 30 Next Last
HT9480
desired output of BZ is 2.73kHz, the frequency
source is 32.768kHz, the values of SPF10 and
SPF11 are both set to 0, and the value of the
programmable frequency divider is set to 5.
Input/Output ports
There are 7 input lines, and 10 input/output
lines in the HT9480, which are labeled as PA,
and PB; PC (PC0, PC1). These are mapped to
[12H], and [14H]; [16H] of the data memory,
respectively. Port A is an input port only while
Port B and Port C (PC0 and PC1) are bidirec-
tional I/O ports. For input operation, the ports
A, B, and C are non-latched, i.e., the inputs have
to be ready at the T2 rising edge of the instruc-
tion “MOV A, [m]” (m=12H, 14H, 16H). For
output operation, data is latched and then re-
mains unchanged until the output latch is re-
written.
The PB and PC (PC0, PC1) I/O lines have their
own control registers (PBC, PCC) to control the
input/output configuration. These control regis-
ters, tri-state (control register=1) or CMOS
(control register=0) with pull-high (option)
structures can be reconfigured dynamically
(i.e., on-the-fly) by software control. To function
as an input, the corresponding I/O latch and
related bit of the control register should be writ-
ten “1” to avoid external logical violation. These
control registers are mapped to location 15H,
and 17H (bit 0 and bit 1 of 17H).
After a chip reset, these input/output lines stay
at high levels or floating (by mask option). They
are defined as input types by writing “1” to the
control registers and as output types by writing
“0” to the control registers. Each bit of these
input/output latches can be set or cleared by
“SET [m].i” and “CLR [m].i” (m=14H only) in-
structions.
Some instructions first input data and then
follow the output operations. For example,
“SET [m].i”, “CLR [m].i”, “CPL [m]”, “CPLA [m]”
read the entire port states into the CPU, exe-
cute the defined operation (bit-operation), and
then write the results back to the latches or the
accumulator.
Each line of port A is capable of waking up the
device (when a falling edge occurs) and is deter-
mined by mask option. The highest four bits of
port C are not physically implemented. Reading
them gets a “0”, but writing them leads to no
operation.
Bit 7 of port A connects a battery fall interrupt
and a wake-up function. Bit 7 of port A wakes
up the µC each time a battery is changed. Bit 2
of port C is used for internal subsystem oscilla-
tor low-power function control (1: non-active; 0
: active). The value of bit 2 of port C is set as “1”
at an initial power on. Bit 3 of port C is used for
LCD power control (1: LCD turn-on; 0 : LCD
turn-off). The value of bit 3 of port C is also set
as “1” at the initial power on.
Input/output ports
21
23th Feb ’98

Share Link: 

datasheetq.com  [ Privacy Policy ]Request Datasheet ] [ Contact Us ]