MRF24XA_15 Datasheet, PDF (71/258 Pages) Microchip Technology – Low-Power, 2.4 GHz ISM-Band IEEE 802.15.4™ RF

MRF24XA
3.0 FUNCTIONAL DESCRIPTION
3.1 Reset
MRF24XA has three reset types:
• Power-On Reset (POR) – MRF24XA has built-in
POR circuitry that automatically resets all control
registers when power is applied. After POR,
MRF24XA starts the internal Calibration process.
RDYIF interrupt is set when the device is ready to
use.
• RESET Pin – Th host MCU can reset MRF24XA by
asserting the RESET pin18 low. All control regis-
ters are reset to default value. If the RESET pin is
deasserted, MRF24XA starts the internal Calibra-
tion process. RDYIF interrupt is set when the
device is ready to use.
• Software Reset – The host MCU can perform the
Software Reset through the SPI interface.
REGRST register (0x00) provides reset signals for
the Configuration registers, while FSMRST register
(0x01) provides reset functionality for the internal
state machines. The reset signals are
asynchronous and the level is evaluated
immediately without any internal synchronization.
The recommended reset sequences:
- FSMRST = 0x1F
- REGRST = 0x3F
- REGRST = 0x00
REGISTER 3-1:
R-00
r
bit 7
REGRST (CONFIGURATION RESET)⁽¹⁾
R/W-000000
REGRST<5:0>
ADDRESS: 0x00
bit 0
Legend: R = Readable bit W = Writable bit
-n = Value at POR
‘1’ = Bit is set
r = Reserved
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-6
bit 5-0
Reserved: Maintain as ‘0’
REGRST<5:0>: Asynchronous Register Reset Field bits
111111 = Reset Configuration registers to default
000000 = Release from reset
Note 1: After setting the field, the host MCU must also clear it to release the device from reset.
REGISTER 3-2: FSMRST (CONTROLLER RESET)⁽¹⁾
R-000
r
bit 7
R/W-00000
FSMRST<4:0>
ADDRESS: 0x01
bit 0
Legend: R = Readable bit W = Writable bit
-n = Value at POR
‘1’ = Bit is set
r = Reserved
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared
x = Bit is unknown
bit 7-5
bit 4-0
Reserved: Maintain as ‘0’
FSMRST<4:0>: Asynchronous Functional Reset Field bits
11111 = Reset state machines to default
00000 = Release from reset
Note 1: After setting the field, the host MCU must clear it to release the device from reset.
 2015 Microchip Technology Inc.
Preliminary
DS70005023C-page 71