LC7234 Просмотр технического описания (PDF) - SANYO -> Panasonic

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производитель

LC7234

CMOS IC - Singlchip PLL and microcontroller with LCD driver

SANYO -> Panasonic 

Standby Mode

LC7234

Note

Ports A to H, S1 to S23, COM1 and COM2 are open.

Functional Description

LCD Driver

The LC7234 can drive LCD segments. The LCP and LCD instructions transfer data to the LCD outputs. The LCD

instruction transfers data directly to the LCD outputs. The LCP instruction converts data to 7-segment format before

transfer to the outputs.

S1 to S23 are the driver outputs. The LCD frame rate is 100Hz with a 50% duty cycle. After reset or power-up, a blank

signal is present on all outputs. In standby mode, all outputs are LOW. They can be used as general-purpose outputs if

the appropriate mask option is selected.

COM1 and COM2 are the LCD common driver outputs. Output drive is 50% duty with 50% bias. Upon reset or after

power-up, the normal drive signals are present on these outputs. In standby mode, all outputs are LOW.

Frequency Counter

Frequency measurement is performed at the HCTR input by the 20-bit universal counter. The input frequency range is

0.4 to 12MHz, which is used for measuring AM and FM IF frequencies. Capacitive coupling should be used.

Phase-Locked Loop

The FMIN or AMIN input signal is divided down by a programmable divider, and then compared with the crystal

frequency, which is also divided down using 14 selectable ratios. The phase difference between the two signals is

measured using a phase detector and output on EO.

FMIN is the input pin for the FM VCO input signal. The input frequency range is 10 to 130MHz. Capacitive coupling

should be used.

AMIN is the AM VCO input. The bandwidth is adjustable in two ranges by using the PLL instruction-HIGH (2 to

40MHz) for the SW band, and LOW (0.5 to 10MHz), for the LW and MW bands. Capacitive coupling should be used.

Input/Output Ports

Port A

This input port has a low switching threshold, which is used for keypad matrix inputs. Pull-down resistors for all pins

are available as a mask option. Note that either all or none of the pins should have pull-down resistors. In standby

mode, inputs are ignored.

Ports B and C

These output ports have unbalanced CMOS outputs which are used as keypad matrix scan outputs. Upon reset, outputs

are set LOW, and in standby mode, outputs are high impedance. The outputs can be short-circuited.

Port E

The transfer direction of this input/output port is selected automatically under software control. When an input instruc-

tion (IN, TPT, or TPF) is executed, port E is configured for input operation, and an output instruction (OUT, SPB or

RPB), for output operation. Upon reset, all pins become inputs. In standby mode, the output drivers are high imped-

ance and the input signals are ignored. All bits should either be inputs or outputs.

No.3620–7/12

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