73S1215F Maxim, 73S1215F Datasheet - Page 74

• Manufacturer Part Number: 73S1215F
• Description: The Teridian 73S1215F is a self-contained SoC smart card reader IC that is an ideal solution for any USB-connected ISO 7816 design
• Manufacturer: Maxim

D- signals to provide the proper impedance matching on these pins.
The USB peripheral block is not able to support read or write operations to the USB SFR registers when
the MPU clock is running at MPU clock rates of 12MHz or greater. In order to properly communicate with
the USB SFR registers when running at these speeds, wait states must be inserted when addressing the
USB SFRs. The CKCON register allows wait states to be inserted when accessing these registers. The
proper settings for the number of wait states are shown in Error! Reference source not found..
Changing these parameters while the USB interface is active may cause communication errors on
the USB interface.
1.7.14.1 USB Interface Implementation
The 73S1215F Application Programming Interface includes some dedicated software commands to
configure the USB interface, to get a status of each USB Endpoint, to stall / unstall portions of the USB,
and to send / receive data to / from each endpoint.
USB API entirely manages the USB circuitry, the USB registers and the FIFOs. Use of those commands
facilitates USB implementation, without dealing with low-level programming.
Miscellaneous Control Register 1 (MISCtl1): 0xFFF2
Note: When using the USB on the 73S1215F, external 24Ω series resistors must be added to the D+ and
74
MISCtl1.7
MISCtl1.6
MISCtl1.5
MISCtl1.4
MISCtl1.3
MISCtl1.2
MISCtl1.1
MISCtl1.0
MSB
Bit
When changing the MPU clock rate or the number of wait states, the USB connection
must be inactive. If the USB is active, then it must be inactivated before changing the
MPU clock or number of wait states. It can then be reconnected and re-enumerated.
–
USBCON
ANAPEN
USBPEN
Symbol
FLSH66
FRPEN
–
–
–
–
FRPEN
Flash Read Pulse enable.
Flash Read Pulse.
Analog power enable.
0 = Enable the USB differential transceiver.
1 = Connect pull-up resistor from VDD to D+. If connected, the USB
host will recognize the attachment of a USB device and begin
enumeration.
Table 78: The MISCtl1 Register
FLSH66
–
0x10
ANAPEN USBPEN USBCON
Function
LSB
Rev. 1.4