ADVANCE INFORMATION
HAL815
Micronas
21
5.3. Telegram Codes
Sync Bit
Each telegram starts with the Sync Bit. This logical “0”
pulse defines the exact timing for t
p0
.
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
exact timing for t
pOUT
.
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.