at88rf256-12 ATMEL Corporation, at88rf256-12 Datasheet - Page 7

• Manufacturer Part Number: at88rf256-12
• Description: 125 Khz Rfid Transponder Chip
• Manufacturer: ATMEL Corporation

Option Page
Bits are listed below in the order in which they must be sent
t o th e c hi p wh e n t h e “ W r i t e Lo c k B y t e ” o r “ W r i t e
Configuration Bits” command is sent to the chip. The
“Default” column lists the values that will be in the die upon
shipment from Atmel.
When reading this page, all 32 bits are read in this order.
This page cannot be written with a single 32-bit command.
Lock Byte
Configuration Bits
Name
LOCK[7:0]
Name
PU_LEN[3:0]
STRT_STOP
STOP_1
RANDOM[1:0]
TST_EN
PW_ON
TCLK_GEN[5:0]
RCLK_GEN
ENCODE[1:0]
INV_ENC
MODULATE[1:0]
PW_LOCK
CONFIG_LOCK
#
8
#
4
1
1
2
1
1
6
1
2
1
2
1
1
Default
Default
0x80
00
10
00
1
1
0
0
0
1
0
0
0
0
Description
Value of stop bit, start bit is opposite value. Default is stop = 1, start = 0.
Frames (ID + 8 transmit bit time listening window) between ID transmissions:
Test mode, leave at 0.
Password enable, if 1 password is page 9 of EEPROM.
Transmit range of 16 clocks/bit to 1024 clocks/bit: (value+1)*16 = # clocks/bit. Default is
16 clocks per bit.
Receive range of 32 clocks/bit to 4096 clocks/bit. Default is 64 clocks per bit.
First stage encoding scheme for transmission. Default is Miller.
Modulator control scheme for transmission. Default is AM.
Locks the password page against further writes.
Locks the configuration page (but not LOCK[7:0] against further writes).
Number of ID bytes after first 4. Total ID size range: 4 - 19 bytes.
Start Stop bit enable. If 1 both start and stop bits will be sent, the default.
Output of encoder is inverted before input to modulator.
Description
If 1, locks the corresponding user page against further writes. Page 7 contains the serial
number and is locked on shipment from the factory.
0 = (tclk clocks/bit)*2
1 = (tclk clocks/bit)*4
00 = No encoding (NRZ)
01 = Manchester
10 = Miller
11 = None (NRZ)
00 = No special modulation (AM / ASK)
01 = PSK1, phase shift on every logic 1, sampled at beginning of bit time.
10 = PSK2, phase shift on every state change at beginning or middle of bit.
11 = Subcarrier gating of 62.5 kHz clock
00 Continuous frames
01 Random null frames, mean number = 8
10 Random null frames, mean number = 32
11 Random null frames, mean number = 128
The “Write Lock Byte” command is used for the first byte
only, and the “Write Configuration Bits” command is used
for the last three bytes.
The “Default” column reflects the default value that the
options have upon shipment from the Atmel factory.
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