73S1217F Maxim, 73S1217F Datasheet - Page 24

• Manufacturer Part Number: 73S1217F
• Description: The Teridian 73S1217F is a self-contained SoC smart card reader IC that is an ideal solution for any USB-connected ISO 7816 design
• Manufacturer: Maxim

The master clock control register enables different sections of the clock circuitry and specifies the value
of the VCO Mcount divider. The MCLK must be configured to operate at 96MHz to ensure proper
operation of some of the peripheral blocks according to the following formula:
Mcount is configured in the
crystal or external clock frequencies for getting MCLK = 96MHz are shown in Table 11.
Master Clock Control Register (MCLKCtl): 0x8F
The MPU clock that drives the CPU core defaults to 3.6923MHz after reset. The MPU clock is scalable
by configuring the MPU Clock Control register (MPUCKCtl).
24
MCLKCtl.7
MCLKCtl.6
MCLKCtl.5
MCLKCtl.4
MCLKCtl.3
MCLKCtl.2
MCLKCtl.1
MCLKCtl.0
Bit
HSOEN
MSB
Symbol
HSOEN
USBEN
32KEN
MCT.2
MCT.1
MCT.0
KBEN
SCEN
Table 11: Frequencies and Mcount Values for MCLK = 96MHz
KBEN
MCLKCtl
High-speed oscillator disable. When set = 1, disables the high-speed crystal
oscillator and VCO/PLL system. Do not set this bit = 1.
1 = Disable the keypad logic clock.
1 = Disable the smart card logic clock.
1 = Disable the USB logic clock.
1 = Disable the 32Khz oscillator. When the 32kHz oscillator is enabled, the
RTC and other circuits such as debounce clocks are clocked using the
32kHz oscillator output. When disabled, the main oscillator provides the
32kHz clock for the RTC and other circuits. Note: This bit must be set if
there is no 32KHz crystal. Some internal clocks and circuits will not
run if the oscillator is enabled and no crystal is connected.
This value determines the ratio of the VCO frequency (MCLK) to the
high-speed crystal oscillator frequency such that:
MCLK = (MCount*2 + 4)* F
MCLK = (2*2 + 4)*12.00MHz = 96MHz.
MCLK = (Mcount * 2 + 4) * F
SCEN
Table 12: The MCLKCtl Register
register must be bound between a value of 1 to 7. The possible
F
USBEN 32KEN
XTAL
12.00
9.60
8.00
6.86
6.00
(MHz)
0x0A
XTAL
Mcount (N)
XTAL
. The default value is MCount = 2h such that
MCT.2
Function
2
3
4
5
6
= 96MHz
MCT.1
MCT.0
LSB
Rev. 1.2