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SLOS758G – DECEMBER 2011 – REVISED MARCH 2020
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Detailed Description
Copyright © 2011–2020, Texas Instruments Incorporated
6.14.1.2.3 TX Pulse Length Control Register (0x06)
describes the bit fields of the TX Pulse Length Control register. This register controls the length
of TX pulse.
Default Value:
0x00, set at POR = H or EN = L and at each write to ISO Control register
The length of the modulation pulse is defined by the protocol selected in the ISO Control register (0x01).
With a high-Q antenna, the modulation pulse is typically prolonged, and the tag detects a longer pulse
than intended. For such cases, the modulation pulse length can be corrected by using the TX pulse length
register 0x06. If the register contains all zeros, then the pulse length is governed by the protocol selection.
If the register contains a value other than 0x00, the pulse length is equal to the value of the register in
73.7-ns increments. This means the range of adjustment can be 73.7 ns to 18.8 µs.
Table 6-21. TX Pulse Length Control Register (0x06)
BIT NO.
BIT NAME
FUNCTION
DESCRIPTION
B7
Pul_p2
Pulse length. B7 is the
MSB.
The pulse range is 73.7 ns to 18.8 µs (1 to 255), step size 73.7 ns
All bits low (00) = Pulse length control is disabled
The following default timings are preset by the ISO Control register (0x01):
2.36 µs for ISO/IEC 14443 A at 106 kbps
1.4 µs for ISO/IEC 14443 A at 212 kbps
737 ns for ISO/IEC 14443 A at 424 kbps
442 ns for ISO/IEC 14443 A at 848 kbps; pulse length control disabled
B6
Pul_p1
B5
Pul_p0
B4
Pul_c4
B3
Pul_c3
B2
Pul_c2
B1
Pul_c1
B0
Pul_c0
6.14.1.2.4 RX No Response Wait Time Register (0x07)
describes the bit fields of the RX No Response Wait Time register. This register defines the
time when no response interrupt is sent.
Default Value:
0x0E, set at POR = H or EN = L and at each write to ISO Control register
The RX no response timer is controlled by the RX No Response Wait Time register. This timer measures
the time from the start of slot in the anticollision sequence until the start of tag response. If there is no tag
response in the defined time, an interrupt request is sent and a flag is set in IRQ Status Control register
(0x0C). This enables the external controller to be relieved of the task of detecting empty slots. The wait
time is stored in the register in increments of 37.76 µs. This register is also preset, automatically, for every
new protocol selection.
Table 6-22. RX No Response Wait Time Register (0x07)
BIT NO.
BIT NAME
FUNCTION
DESCRIPTION
B7
NoResp7
No response. B7 is the
MSB.
Defines the time when the
no response
interrupt is sent. Timing starts from
the end of TX EOF. RX no response wait range is 37.76 µs to 9628 µs (1 to
255). Step size is 37.76 µs.
The following default timings are preset by the ISO Control register (0x01):
529 µs for for all protocols
B6
NoResp6
B5
NoResp5
B4
NoResp4
B3
NoResp3
B2
NoResp2
B1
NoResp1
B0
NoResp0
