* Question
How to address the internal registers of the MF RC500?
* Answer
The MF RC500 RFID controller features a paged register architecture consisting of 64 internal registers. These registers are organized across 8 logical pages, with 8 registers per page. To access a specific register, the user must first select the appropriate page via the Page Register, then address the target register within that page.
1. Paged Register Structure
The internal address space is divided into 8 pages (Page 0 to Page 7).
Each page contains 8 registers, addressed from 0x00 to 0x07 within the page.
The Page Register is located at addresses such as 0x00, 0x08, 0x10, etc., each corresponding to the start of a new page.
2. Page Selection Mechanism
The Page Register includes two key bit fields:
UsePageSelect (bit 7):
When set to 1, enables external page selection. The PageSelect field determines the active page.
When set to 0, the device bypasses paging and uses the internally latched full address.
PageSelect (bits 2–0):
Selects one of the eight logical pages (values 0 to 7).
3. Register Access Procedure
To access a specific internal register, follow these steps:
Set the Page Register:
Write to the Page Register to enable paging (UsePageSelect = 1) and define the target page via PageSelect. For example, to access Page 1, write 0x81 to the Page Register.
Specify the Register Address within the Page:
Use address lines A0–A2 to select the target register (offset 0x00 to 0x07).
Perform Read or Write Operation:
Address and data are multiplexed over lines AD0–AD7.
Control signals include:
ALE (Address Latch Enable)
NWR (Write Enable)
NRD (Read Enable)
NCS (Chip Select)
4. Example: Writing to the CONTROL Register (Address 0x09)
To write to the CONTROL register, which resides on Page 1:
Write 0x81 to the Page Register at address 0x08 to enable Page 1.
Address register offset 0x01 (first register of Page 1).
Send the data using the parallel interface with appropriate control signals.
5. Summary
Total Registers: 64
Page Structure: 8 pages × 8 registers
Access Method: Set Page Register, then address within page
Interface: 8-bit parallel bus (address/data multiplexed)
Control Lines: ALE, NWR, NRD, NCS
This addressing scheme enables efficient access to all internal registers of the MF RC500. The described method aligns with the official datasheet specifications and is suitable for common RFID reader design applications.
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