TPMC917 User Manual Issue 1.0.7
Page 6 of 26
1 Product Description
The TPMC917 is a standard single-width 32 bit PMC module providing 4 Mbyte SRAM with battery
backup by an on board lithium cell for all SRAM devises and four ESD protected RS232 channels
(TPMC917-10 only).
The 4 Mbyte NV-SRAM is organized in two banks, each of them provides 512k x 32 bit memory.
During normal operation (standard 5V supply applied to the SRAM) the capacity of the lithium cell is
monitored every 24 hours by the battery monitor device and an interrupt can be generated, if the
battery voltage is too low. The monitor device switches the power supply of the SRAM from the
standard 5V to the battery if the 5V supply drops below the threshold level of the battery monitor
device. Any active access to the SRAM at this point is executed correctly within 1.5µs. After this time
any further accesses to the SRAM are not possible. A miniature DIP switch allows the selection of the
battery backup source either from the on board lithium cell or from an external battery via the P14 I/O
connector.
The TPMC917-10 provides four RS232 channels. Each channel has a programmable baud rate up to
115.2 Kbaud. The 4 channel UART16C654 provides 64 byte transmit FIFO and 64 byte receive FIFO
for each channel to significantly reduce the overhead required to provide data to and get data from the
transmitter and receiver. The FIFO trigger levels are programmable. The channels are ESD protected
up to +/-15kV according to the human body model and IEC1000-4-2.
For applications which do not need the UARTs of the TPMC917-10, the TPMC917-20 provides
4 MByte NV-SRAM and has no UARTs.
The TPMC917-21 has a reduced memory size. It provides 2 MByte NV-SRAM and has no UARTs.
Figure 1-1 : Block Diagram
CAUTION! - This system contains a lithium battery. Lithium batteries may explode if
mishandled.
Please refer to chapter “Security Warning (Lithium Battery)”.
