Rev. 1.00
170
September 11, 2018
Rev. 1.00
171
September 11, 2018
HT45F4050
A/D NFC Flash MCU
HT45F4050
A/D NFC Flash MCU
As shown in the CC3 bit description, if CC3=00h, the NFC Forum Type 2 Tag Capability bytes are
set and allow read/write access. If CC3=0Fh, the NFC Forum Type 2 Tag Capability bytes are set
and only allow read access. If CC3=other values, the NFC Forum Type 2 Tag Capability bytes are
set and do not allow read and write access. Note that when the CC3 byte is configured with 0Fh or
other values except 00h, it means a "soft-lock" only and does not physically lock the corresponding
memory.
The Capability Container bytes in page 03h are programmed during IC production according to the
NFC Forum Type Tag specification. The corresponding bytes of the WRITE or COMPATIBILITY_
WRITE command to page 03h and the current contents of the CC bytes are bit-wise OR’ed, after
which the results become the new contents of the CC bytes. This process is irresversible and once a
bit is set to "
1
" it can not be changed back to "
0
" directly by the RF interface.
The default value of the CCn byte is E1h,
10
h,
26h and 00h for n=0~3 respectively
.
The example
below will illustrate how to generate the new CCn bytes content. However, to maintain compatibility
with the NFC Forum Type 2 Tag specification and interoperability with different NFC devices, it is
not recommended to change the default capability container contents.
• Page 3 default value – initial state
Bytes
CC0
CC1
CC2
CC3
Default Value
11100001
00010000
00100110
00000000
• Write command to page 3 CCn Byte
Bytes
CC0
CC1
CC2
CC3
Written Value
00000000
00000000
00000000
00001111
The written value will not be directly written into the corresponding CCn byte. An "OR" operation
will be executed for the written value and the current content for the CCn byte. After this the "OR"
operation result will be written into the corresponding CCn byte as shown in the following table.
• Result in page 3 CCn Byte – read-only state
Bytes
CC0
CC1
CC2
CC3
Read Value
11100001
00010000
00100110
00001111
NFC Control Registers
The NFC module is controlled by several registers. An interrupt enable register is used to control
various NFC related interrupt functions and an interrupt flag register exists to indicate the
corresponding interrupt requests. A status register indicates the NFC operation state. Six registers
including one page address register, four data registers and a control register together control the
MCU access operation to the internal NFC memory. A read/write register controls the functions
including modulation mode selection, field detect interrupt enable condition selection and NFC
module enable/disable function. Finally a read only register exists to store the last NFC memory
page address written by the RF.