
MICRF500
Programming
A two-line bus is used to program the circuit; the two lines
being CLKIN and REGIN. The 2-line serial bus interface
allows control over the frequency dividers and the selective
powering up of Tx, Rx and Synthesizer circuit blocks. The
Micrel
interface consists of an 80-bit programming register. Data is
entered on the REGIN line with the most significant bit first.
The first bit entered is called p1, the last one p80. The bits in
the programming register are arranged as shown in Table 1.
p1 – p6
A1
p59
Pa1
p67
Ref2
p75
OutS1
p7 - p12
A0
p60
Pa0
p68
Ref1
p76
OutS0
p13 – p24
N1
p61
Gc
p69
Ref0
p77
Mod1
p25 – p36
N0
p62
ByLNA
p70
Cpmp1
p78
Mod0
p37 – p46
M1
p63
Ref6
p71
Cpmp0
p79
RT
p47 – p56
M0
p64
Ref5
p72
Fc1
p80
Pu
p57
RxFilt
p65
Ref4
p73
Fc0
—
—
p58
Pa2
p66
Ref3
p74
OutS2
—
—
Table 1. Bit Allocation
MICRF500
14
March 2003