Micrel MICRF505BML/YML
August 2006 9
M9999-092904
+1 408-944-0800
Programming
General
The MICRF505 functions are enabled through a
number of programming bits. The programming bits
are organized as a set of addressable control
registers, each register holding 8 bits.
There are 23 control registers in total in the
MICRF505, and they have addresses ranging from 0
to 22. The user can read all the control registers.
The user can write to the first 22 registers (0 to 21);
the register 22 is a read-only register.
All control registers hold 8 bits and all 8 bits must be
written to when accessing a control register, or they
will be read. Some of the registers do not utilize all 8
bits. The value of an unused bit is “don’t care.”
The control register with address 0 is referred to as
ControlRegister0, the control register with address 1
is ControlRegister1 and so on. A summary of the
control registers is given in the table below. In
addition to the unused bits (marked with”-“) there are
a number of mandatory bits (marked with “0” or “1”).
Always maintain these as shown in the table.
The control registers in MICRF505 are accessed
through a 3-wire interface; clock, data and chip
select. These lines are referred to as SCLK, IO, and
CS, respectively. This 3-wire interface is dedicated
to control register access and is referred to as the
control interface. Received data (via RF) and data to
transmit (via RF) are handled by the DataIXO and
DataClk (if enabled) lines; this is referred to as the
data interface.
The SCLK line is applied externally; access to the
control registers are carried out at a rate determined
by the user. The MICRF505 will ignore transitions on
the SCLK line if the CS line is inactive. The
MICRF505 can be put on a bus, sharing clock and
data lines with other devices.
All control registers should be written to after a
battery reset. During operation, it is sufficient to write
to one register only. The MICRF505 will
automatically enter power down mode after a battery
reset.
Adr Data
A6…A0 D7 D6 D5 D4 D3 D2 D1 D0
0000000 LNA_by PA2 PA1 PA0 Sync_en Mode1 Mode0 Load_en
0000001 Modulation1 Modulation0 ‘0’ ‘0’ RSSI_en LD_en PF_FC1 PF_FC0
0000010 CP_HI SC_by ‘0’ PA_By OUTS3 OUTS2 OUTS1 OUTS0
0000011 ‘1’ ‘1’ ‘0’ VCO_IB2 VCO_IB1 VCO_IB0 VCO_freq1 VCO_freq0
0000100 Mod_F2 Mod_F1 Mod_F0 Mod_I4 Mod_I3 Mod_I2 Mod_I1 Mod_I0
0000101 - - ‘0’ ‘1’ Mod_A3 Mod_A2 Mod_A1 Mod_A0
0000110 - Mod_clkS2 Mod_clkS1 Mod_clkS0 BitSync_clkS2 BitSync_clkS1 BitSync_clkS0 BitRate_clkS2
0000111 BitRate_clkS1 BitRate_clkS0 RefClk_K5 RefClk_K4 RefClk_K3 RefClk_K2 RefClk_K1 RefClk_K0
0001000 ‘1’ ‘1’ ScClk5 ScClk4 ScClk3 ScClk2 ScClk1 ScClk0
0001001 ‘0’ ‘0’ ‘1’ XCOtune4 XCOtune3 XCOtune2 XCOtune1 XCOtune0
0001010 - - A0_5 A0_4 A0_3 A0_2 A0_1 A0_0
0001011 - - - - N0_11 N0_10 N0_9 N0_8
0001100 N0_7 N0_6 N0_5 N0_4 N0_3 N0_2 N0_1 N0_0
0001101 - - - - M0_11 M0_10 M0_9 M0_8
0001110 M0_7 M0_6 M0_5 M0_4 M0_3 M0_2 M0_1 M0_0
0001111 - - A1_5 A1_4 A1_3 A1_2 A1_1 A1_0
0010000 - - - - N1_11 N1_10 N1_9 N1_8
0010001 N1_7 N1_6 N1_5 N1_4 N1_3 N1_2 N1_1 N1_0
0010010 - - - - M1_11 M1_10 M1_9 M1_8
0010011 M1_7 M1_6 M1_5 M1_4 M1_3 M1_2 M1_1 M1_0
0010100 ‘1’ ‘0’ ‘1’ ‘1’ ‘0’ ‘1’ ‘0’ ‘1’
0010101 - - - - FEEC_3 FEEC_2 FEEC_1 FEEC_0
0010110 FEE_7 FEE_6 FEE_5 FEE_4 FEE_3 FEE_2 FEE_1 FEE_0
Names of programming bits, unused bits (“-“) and mandatory bits (“1” or “0”) are shown. Change of mandatory bits may cause malfunction.
Table 1. Control Registers in MICRF505
