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 12 of 222
NXP Semiconductors
PN532/C1
Near Field Communication (NFC) controller
8.1.2 Data memory
Data memory is itself divided into 2 spaces:
384-byte IDATA with byte-wide addressing
258-byte RAM
128-byte SFR
1 bank of 64 KB extended RAM (XRAM) with 2-byte-wide addressing
8.1.2.1 IDATA memory
The IDATA memory is mapped into 3 blocks, which are referred as Lower IDATA RAM,
Upper IDATA RAM, and SFR. Addresses to these blocks are byte-wide, which implies an
address space of only 256 bytes. However, 384 bytes can be addressed within IDATA
memory through the use of direct and indirect address mechanisms.
Direct addressing: the operand is specified by an 8-bit address field in the instruction.
Indirect addressing: the instruction specifies a register where the address of the
operand is stored.
For the range 80h to FFh, direct addressing will access the SFR space; indirect
addressing accesses Upper IDATA RAM. For the range 0h0 to 7Fh, Lower IDATA RAM is
accessed, regardless of addressing mode. This behavior is summarized in the table
below:
The SFRs and their addresses are described in the Table 5:
Table 4. IDATA memory addressing
Address Addressing mode
Direct Indirect
00h to 7Fh Lower IDATA RAM Lower IDATA RAM
80h to FFh SFRs Upper IDATA RAM