User Guide

CC Technical Documentation System Module

RM-11

Flash Memory Description

The 128 Mbit density flash with 16-bit data access operates in both asynchronous

random access and synchronous burst access (with crossing partition boundaries) and

has various data protection features. Upon power up or reset, the device defaults to

asynchronous read configuration. Synchronous burst read is indicated to the device by

writing to the flash configuration register and can be terminated by deactivating the

device.

The device supports reads and in-system erase and program operations at Vcc=1.8 V

(Voltage range 1.7-1.9 V). Flashing at production is supported at Vpp=12 V (for limited

exposure length only).

Flash Architecture

The datasheet of RM-11 combo memory contains detailed information about Flash

architecture.

Keyboard (UI Module)

The RM-11 consists of a separate UI board and includes contacts for the keypad domes

and LEDs for keypad lighting. The UI board is connected to the main PWB through a

16-pole, board-to-board connector with springs. A 5x4 matrix keyboard is also used. Key

pressing is detected by a scanning procedure. Keypad signals are connected via the UPP

keyboard interface.

When no key is pressed, row inputs are high due to UPP internal pull-up resistors. The

columns are written zero. When a key is pressed, one row is pulled down and an interrupt

is generated to the MCU. After receiving the interrupt, the MCU starts the scanning

procedure. All columns are first written high and then one column at a time is written

down. All columns, except the column that is written down, are set as inputs. Rows are

read while a column at the time is written down. If a row is down, it indicates that key,

which is at the cross point of the selected column and row that was pressed. After

detecting the pressed key, all registers inside the UPP are reset and columns are written

back to zero.

Keyboard ESD Protection

The SMD chips LEDs on the UI board have 2kV ESD protection. In case the A-cover is

removed, there is a potential risk of damaging the LEDs with electrostatic discharge.

Ground openings are made around LEDs to catch ESD sparks. For additional protection,

the dome sheet is made of conductive metallized tape and grounded to the display

shield.