Datasheet

Table Of Contents
PN532_C1 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2017. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 3.6 — 28 November 2017
115436 141 of 222
NXP Semiconductors
PN532/C1
Near Field Communication (NFC) controller
8.6.21.2 CIU test bus
The test bus is implemented for production test purposes. The following configuration can
be used to improve the design of a system using the PN532. The test bus allows to route
internal signals to output pins.
The Observe_testbus register is used to enable this functionality.
The test bus signals are selected by accessing TestBusSel in register CIU_TestSel2.
Table 169. Observe_testbus register (address 6104h) bit allocation
Bit 7 6 5 4 3 2 1 0
Symbol -------observe_ciu
Reset 0000000 0
Access RRRRRRR R/W
Table 170. Description of Observe_testbus bits
Bit Symbol Description
7 to 1 - Reserved.
0 observe_ciu Configure the pads P3x (P30 to P35), RSTOUT_N and P70_IRQ to
observe internal CIU data bus.
When set to logic 1, the pads are configured in output mode and show
the internal data bus D0 to D6 of the CIU. P70_IRQ is the 13.56 MHz
digital clock of CIU (generated from field or crystal).
Table 171. TstBusBitSel set to 07h
Test bus bit Test signal Comments
D6 sdata shows the actual received data value.
D5 scoll shows if in the actual bit a collision has been detected
(106 kbit/s only)
D4 svalid shows if sdata and scoll are valid
D3 sover shows that the receiver has detected a stop bit
(ISO/IEC 14443A/MIFARE mode only)
D2 RCV_reset shows if the receiver is reset
D1 RFon filtered shows the value of the internal RF level detector
D0 Envelope shows the output of the internal coder
Table 172. TstBusBitSel set to 0Dh
Test bus bit Test signal Comments
D6 clkstable shows if the oscillator delivers a stable signal
D5 clk27/8 shows the output signal of the oscillator divided by 8
D4 clk27rf/8 shows the clk27rf signal divided by 8
D3 clk13/4 shows the clk13rf divided by 4
D2 clk27 shows the output signal of the oscillator
D1 clk27rf shows the RF clock multiplied by 2
D0 clk13rf shows the RF clock of 13.56 MHz