ADVANCE INFORMATION

HAL 815

Micronas

21

5.3. Telegram Codes

Sync Bit

Each telegram starts with the Sync Bit. This logical “0”

Command Bits (COM)

The Command code contains 3 bits and is a binary

number. Table 5–2 shows the available commands and

the corresponding codes for the HAL 815.

Command Parity Bit (CP)

This parity bit is “1” if the number of zeros within the 3

Command Bits is uneven. The parity bit is “0”, if the

number of zeros is even.

Address Bits (ADR)

The Address code contains 4 bits and is a binary num-

ber. Table 5–3 shows the available addresses for the

HAL 815 registers.

Address Parity Bit (AP)

This parity bit is “1” if the number of zeros within the 4

Address bits is uneven. The parity bit is “0” if the num-

ber of zeros is even.

Data Bits (DAT)

The 14 Data Bits contain the register information.

The registers use different number formats for the

Data Bits. These formats are explained in Section 5.4.

In the Write command, the last bits are valid. If, for

example, the TC register (6 bits) is written, only the

last 6 bits are valid.

In the Read command, the first bits are valid. If, for

example, the TC register (6 bits) is read, only the first 6

bits are valid.

Data Parity Bit (DP)

This parity bit is “1” if the number of zeros within the

binary number is even. The parity bit is “0” if the num-

ber of zeros is uneven.

Acknowledge

After each telegram, the output answers with the

Acknowledge signal. This logical “0” pulse defines the

Table 5–2: Available commands

Command

Code

Explanation

READ

2

read a register

WRITE

3

write a register

PROM

4

program all nonvolatile registers (except the lock bits)

ERASE

5

erase all nonvolatile registers (except the lock bits)

LOCKI

6

lock Micronas lockable register

LOCK

7

lock the whole device and switch permanently to the analog-mode

Please note:

The Micronas lock bit (LOCKI) has already been set during production and cannot be reset.