CR14-MQP STMicroelectronics, CR14-MQP Datasheet - Page 14

• Manufacturer Part Number: CR14-MQP
• Manufacturer: STMicroelectronics

Specifications of CR14-MQP

• Pin Count: 16
• Screening Level: Commercial
• Lead Free Status / Rohs Status: Compliant

CR14 registers
Table 4.
3.3
Table 5.
14/47
Frame Length
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
00h No Byte transmitted
FFh CRC Error
xxh Number of transmitted Bytes
Byte 0
Status Slot
Status Slot
Input/output frame register description
Slot marker register (03h)
The slot Marker Register is located at the I²C address 03h. It is used to trigger an automated
anti-collision sequence between the CR14 and any ST short range memory present in the
electromagnetic field. With one I²C access, the CR14 launches a complete stream of
commands starting from PCALL16(), SLOT_MARKER(1), SLOT_MARKER(2) up to
SLOT_MARKER(15), and stores all the identified Chip_IDs into the Input/Output Frame
Register (I²C address 01h).
This automated anti-collision sequence simplifies the host software development and
reduces the time needed to interrogate the 16 slots of the STMicroelectronics anti-collision
mechanism.
When accessed in I²C Write mode, the Slot Marker Register starts generating the sequence
of anti-collision commands. After each command, the CR14 wait for the ST short range
memory answer frame which contains the Chip_ID. The validity of the answer is checked
and stored into the corresponding Status Slot Bit (Byte 1 and Byte 2 as described in
Table
into the corresponding Slot_Register. If no answer is detected, the Status Slot Bit is set to
‘0’, and the corresponding Slot_Register is set to 00h. If a CRC error is detected, the Status
Slot Bit is set to ‘0’, and the corresponding Slot_Register is set to FFh.
Each time the Slot Marker Register is accessed in I²C Write mode, Byte 0 of the
Input/Output Frame Register is set to 18, Bytes 1 and 2 provide Status Bits Slot information,
and Bytes 3 to 18 store the corresponding Chip_ID or error code.
The Slot Marker Register cannot be accessed in I²C Read mode. All the anti-collision data
can be accessed by reading the Input/Output Frame Register at the I²C address 01h.
Slot marker register description
Bit 15
Bit 7
b
7
5). If the answer is correct, the Status Slot Bit is set to ‘1’ and the Chip_ID is stored
First data Byte
Byte 1
Status Slot
Status Slot
<------------- Request and Answer Frame Bytes exchanged on the RF ------------->
Bit 14
Bit 6
b
6
Slot_Register 0 = Chip_ID value detected in Slot 0
Slot_Register 1 = Chip_ID value detected in Slot 1
Slot_Register 2 = Chip_ID value detected in Slot 2
Status Slot
Status Slot
Second data Byte
Bit 13
Bit 5
b
5
Number of stored Bytes: fixed to 18
Byte 2
Doc ID 11922 Rev 2
Status Slot
Status Slot
Bit 12
Bit 4
b
4
Byte 3
Status Slot
Status Slot
Bit 11
Bit 3
b
3
...
Status Slot
Status Slot
Bit 10
Bit 2
b
2
Byte 34
Status Slot
Status Slot
Bit 1
Bit 9
b
1
Last data Byte
Byte 35
Status Slot
Status Slot
Bit 0
Bit 8
b
CR14
0