CS2200-OT Datasheet, PDF (14/23 Pages) Cirrus Logic – Fractional-N Frequency Synthesizer

5.6 Mode Pin Functionality
CS2200-OTP
5.6.1
M1 and M0 Mode Pin Functionality
M[1:0] determine the functional mode of the device and select both the default User Defined Ratio and
the set of modal parameters. The modal parameters are RModSel[1:0] and AuxOutSrc[1:0]. By modifying
one or more of the modal parameters between the 4 sets, different functional configurations can be
achieved. However, global parameters are fixed and the same value will be applied to each functional
configuration. Figure 10 on page 17 provides a summary of all parameters used by the device.
5.6.2
M2 Mode Pin Functionality
M2 usage is mapped to one of the optional special functions via the M2Config[2:0] global parameter. De-
pending on what M2 is mapped to, it will either act as an output enable/disable pin or override certain mod-
al parameters. Figure 9 summarizes the available options and the following sections will describe each
option in more detail.
M2Config[2:0] global parameter
M2 pin
000
Disable CLK_OUT pin
001
Disable AUX_OUT pin
010
Disable CLK_OUT and AUX_OUT pins
011
RModSel[1:0] Modal Parameter Enable
100
Reserved
101
Reserved
110
Reserved
111
Force AuxOutSel[1:0] = 10 (PLL Clock Out)
5.6.2.1
5.6.2.2
Figure 9. M2 Mapping Options
M2 Configured as Output Disable
If M2Config[2:0] is set to either ‘000’, ‘001’, or ‘010’, M2 becomes an output disable pin for one or
both output pins. If M2 is driven ‘low’, the corresponding output(s) will be enabled, if M2 is driven
‘high’, the corresponding output(s) will be disabled.
M2 Configured as R-Mod Enable
If M2Config[2:0] is set to ‘011’, M2 becomes the R-Mod enable pin. It should be noted that M2 is
the only way to enable R-Mod. Even though the RModSel[1:0] modal parameter can be set arbi-
trarily for each configuration set, it will not take effect unless enabled via M2. If M2 is driven ‘low’,
R-Mod will be disabled, if M2 is driven ‘high’ R-Mod will be enabled.
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