The ST16C554D is a universal asynchronous receiver
and transmitter (UART) with a dual foot print interface.
The 554D is an enhanced UART with 16 byte FIFOs,
receive trigger levels and data rates up to 1.5Mbps.
Onboard status registers provide the user with error
indications and operational status, modem interface
control. System interrupts may be tailored to meet
user requirements. An internal loopback capability
allows onboard diagnostics. The 554D is available in
64 pin TQFP, and 68 pin PLCC packages. The 68 pin
PLCC package offer an additional 68 mode which
allows easy integration with Motorola, and other popular
microprocessors. The ST16C554CQ64 (64 pin)
offers three state interrupt control while the
ST16C554DCQ64 provides constant active interrupt
outputs. The 64 pin devices do not offer TXRDY/
RXRDY outputs. The 554D combines the package
interface modes of the 16C554 and 68C554 series on
a single integrated chip.