Rev. 1.00
184
September 11, 2018
Rev. 1.00
185
September 11, 2018
HT45F4050
A/D NFC Flash MCU
HT45F4050
A/D NFC Flash MCU
HLTA – Halt Command for Type A
Code (CMD.)
Parameter (PAR.)
Data
Integrity Mechanism
Response
50h
00h
—
Parity, CRC
Passive ACK, NAK
The HLTA command is used to set the recognized NFC tag device into the HALT state. It is simple
to distinguish between devices whose UIDs have been identified and devices whose UIDs have not
been resolved after the recognized NFC tag devices is set into the HALT state. The tag device will
directly enter the HALT state if the HLTA command is fully executed without any error. The HLTA
command can still be fully executed even if an incorrect parity value is contained in the data stream
transmitted by the NFC reader device. However, if the CRC value is incorrect the NFC tag device
will return to the IDLE or HALT state respectively which depends upon the previous state in which
the NFC tag device remains.
50
Command
Tag Device
Response
CMD.
NAK
90
μ
s
00
CRC0 CRC1
PAR.
CRC error
ACK
90
μ
s
HLTA Execution Diagram
WRITE – Write Command
Code (CMD.)
Parameter (PAR.)
Data
Integrity Mechanism
Response
A2h
ADR: ‘02h’ to ‘4Fh’
4 Bytes
Parity, CRC
ACK or NAK
The WRITE command is used to program the NFC tag device memory by page with 4 data bytes.
The page address is specified in the parameter field. The available page address ranges from 02h
to 4Fh. A NAK response will be sent out by the NFC tag device if the page address is outwith the
available range. A parity, CRC or write error will also result in a NAK response with a certain 4-bit
value sent by the NFC tag device. Note that any locked memory pages can not be programmed again
by any write command.
A2
Command
Tag Device
Response
CMD.
ACK
90
μ
s
ADR
CRC0 CRC1
NAK
D0
D1
D2
D3
PAR.
NAK
ADR/CRC/Parity error
Write error
t
WCY
< Response time < *t
COL
+ 2t
WCY
~ ~
2t
WCY
< Response time < *t
COL
+ 2t
WCY
~ ~
*t
COL
: Collision time, including *t
RCY
or *t
WCY
respectively
*t
COL
exists if the collision of the NFC memory access by MCU occurs
WRITE Execution Diagram