SC28L194A1A NXP Semiconductors, SC28L194A1A Datasheet - Page 15

• Manufacturer Part Number: SC28L194A1A
• Description: UART Interface IC 3V-5V 4CH UART INTEL/MOT INTRF
• Manufacturer: NXP Semiconductors
• Type: Quad UART for 3.3 V and 5 V supply voltager

Specifications of SC28L194A1A

• Number Of Channels: 4
• Data Rate: 460.8 Kbps
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 3 V
• Supply Current: 30 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Package / Case: PLCC-68
• Mounting Style: SMD/SMT
• Operating Supply Voltage: 3.3 V, 5 V
• Lead Free Status / Rohs Status: Details
• Other names: SC28L194A1A,512

Philips Semiconductors
Host mode
When neither the auto-receiver nor auto-transmitter modes are set,
the Xon/Xoff logic is operating in the host mode. In host mode, all
activity of the Xon/Xoff logic is initiated by commands to the CRx
command forces the transmitter to disable exactly as though an Xoff
character had been received by the RxFIFO. The transmitter will
remain disabled until the chip is reset or the CR(7:3) = 10110 (Xoff
resume) command is given. In particular, reception of an Xon or
disabling or re-enabling the transmitter will NOT cause resumption
of transmission. Redundant CRTX-- commands, i.e. CRTXon
CRTXon, are harmless, although they waste time. A CRTXon may
be used to cancel a CRTXoff (and vice versa) but both may be
transmitted depending on the timing with the transmit state machine.
The kill CRTX command can be used to cleanly terminate any
CRTX commands pending with the minimum impact on the
transmitter.
Note: In no case will an Xon/Xoff character transmission be aborted.
Once the character is loaded into the TX Shift Register, transmission
continues until completion or a chip reset is encountered.
The kill CRTX command has no effect in either of the Auto modes.
Mode Control
Xon/Xoff mode control is accomplished via the MR0. Bits 3 and 2
reset to zero resulting in all Xon/Xoff processing being disabled. If
MR0[2] is set, the transmitter may be gated by Xon/Xoff characters
received. If MR0[3] is set, the transmitter will transmit Xon and Xoff
when triggered by attainment of fixed fill levels in the channel
RxFIFO. The MR0[7] bit also has an Xon/Xoff function control. If this
bit is set, a received Xon or Xoff character is not pushed into the
RxFIFO. If cleared, the power-on and reset default, the received
Xon or Xoff character is pushed onto the RxFIFO for examination by
the host CPU. The MR0(7) function operates regardless of the value
in MR0(3:2)
Xon/Xoff Interrupts
The Xon/Xoff logic generates interrupts only in response to
recognizing either of the characters in the XonCR or XoffCR (Xon or
Xoff Character Registers). The transmitter activity initiated by the
Xon/Xoff logic or any CR command does not generate an interrupt.
2006 Aug 15
Quad UART for 3.3 V and 5 V supply voltage
15
The character comparators operate regardless of the value in
MR0(3:2). Hence the comparators may be used as general purpose
character detectors by setting MR0(3:2)=’00’ and enabling the
Xon/Xoff interrupt in the IMR.
The Quad UART can present the Xon/Xoff recognition event to
the interrupt arbiter for IRQN generation. The IRQN generation may
be masked by setting bit 4 of the Interrupt Mask Register, IMR. The
bid level of an Xon/Xoff recognition event is controlled by the
Bidding Control Register X, BCRX, of the channel. The interrupt
status can be examined in ISR[4]. If cleared, no Xon/Xoff recognition
event is interrupting. If set, an Xon or Xoff recognition event has
been detected. The X Interrupt Status Register, XISR, can be read
for details of the interrupt and to examine other, non-interrupting,
status of the Xon/Xoff logic. Refer to the XISR in the Register
Descriptions.
The character recognition function and the associated interrupt
generation is disabled on hardware or software reset.
REGISTER DEFINITIONS
The operation of the Quad UART is programmed by writing control
words into the appropriate registers. Operational feedback is
provided via status registers which can be read by the host CPU.
The Quad UART addressing is loosely divided, by the address bit
A(7), into two parts:
1. That part which is concerned with the configuration of the chip
2. That part concerned with the transmission and reception of the
interface and communication modes.
This part controls the elements of host interface setup, interrupt
arbitration, I/O Port Configuration that part of the UART channel
definitions that do not change in normal data handling. This
section is listed in the “Register Map, Control”.
bit streams.
This part concerns the data status, FIFO fill levels, data error
conditions, channel status, data flow control (hand shaking). This
section is listed in the “Register Map, Data”.
SC28L194
Product data sheet