SC16C652B - NXP Semiconductors

SC16C652B
5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.) with 32-byte
FIFOs and infrared (IrDA) encoder/decoder
Rev. 04 — 1 September 2005
Product data sheet
1. General description
The SC16C652B is a 2 channel Universal Asynchronous Receiver and Transmitter
(UART) used for serial data communications. Its principal function is to convert parallel
data into serial data and vice versa. The UART can handle serial data rates up to 5 Mbit/s.
The SC16C652B is pin compatible with the SC16C2550. It will power-up to be functionally
equivalent to the 16C2450. The SC16C652B provides enhanced UART functions with
32-byte FIFOs, modem control interface, DMA mode data transfer, and IrDA
encoder/decoder. The DMA mode data transfer is controlled by the FIFO trigger levels
and the TXRDY and RXRDY signals. On-board status registers provide the user with error
indications and operational status. System interrupts and modem control features may be
tailored by software to meet specific user requirements. An internal loop-back capability
allows on-board diagnostics. Independent programmable baud rate generators are
provided to select transmit and receive baud rates.
The SC16C652B operates at 5 V, 3.3 V and 2.5 V and the industrial temperature range,
and is available in plastic LQFP48 and very small (Micro-UART) HVQFN32 packages.
2. Features
■
■
■
■
■
■
■
■
■
■
■
■
■
■
■
■
■
2 channel UART
5 V, 3.3 V and 2.5 V operation
5 V tolerant inputs
Industrial temperature range (−40 °C to +85 °C)
Pin and functionally compatible to 16C2450 in LQFP48 package, and software
compatible with industry standard 16C450, 16C550, and SC16C650
Up to 5 Mbit/s data rate at 5 V and 3.3 V, and 3 Mbit/s at 2.5 V
32-byte transmit FIFO to reduce the bandwidth requirement of the external CPU
32-byte receive FIFO with error flags to reduce the bandwidth requirement of the
external CPU
Independent transmit and receive UART control
Four selectable Receive and Transmit FIFO interrupt trigger levels
Automatic software (Xon/Xoff) and hardware (RTS/CTS) flow control
Programmable Xon/Xoff characters
Software selectable baud rate generator
Standard modem interface or infrared IrDA encoder/decoder interface
Supports IrDA version 1.0 (up to 115.2 kbit/s)
Sleep mode
Standard asynchronous error and framing bits (Start, Stop, and Parity Overrun Break)
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
■ Transmit, Receive, Line Status, and Data Set interrupts independently controlled
■ Fully programmable character formatting:
◆ 5-bit, 6-bit, 7-bit, or 8-bit characters
◆ Even, odd, or no-parity formats
◆ 1, 11⁄2, or 2-stop bit
◆ Baud generation (DC to 5 Mbit/s)
■ False start-bit detection
■ Complete status reporting capabilities
■ 3-state output TTL drive capabilities for bi-directional data bus and control bus
■ Line break generation and detection
■ Internal diagnostic capabilities:
◆ Loop-back controls for communications link fault isolation
■ Prioritized interrupt system controls
■ Modem control functions (CTS, RTS, DSR, DTR, RI, CD)
3. Ordering information
Table 1:
Ordering information
Type number
Package
Name
Description
Version
SC16C652BIB48
LQFP48
plastic low profile quad flat package; 48 leads; body 7 × 7 × 1.4 mm
SOT313-2
SC16C652BIBS
HVQFN32
plastic thermal enhanced very thin quad flat package; no leads;
32 terminals; body 5 × 5 × 0.85 mm
SOT617-1
SC16C652B_4
Product data sheet
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Rev. 04 — 1 September 2005
2 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
4. Block diagram
SC16C652B
D0 to D7
IOR
IOW
RESET
TRANSMIT
FIFO
REGISTER
TXA, TXB
DATA BUS
AND
CONTROL
LOGIC
REGISTER
SELECT
LOGIC
INTERCONNECT BUS LINES
AND
CONTROL SIGNALS
FLOW
CONTROL
LOGIC
A0 to A2
CSA
CSB
TRANSMIT
SHIFT
REGISTER
RECEIVE
FIFO
REGISTER
FLOW
CONTROL
LOGIC
IR
ENCODER
RECEIVE
SHIFT
REGISTER
RXA, RXB
IR
DECODER
DTRA, DTRB
RTSA, RTSB
OP2A, OP2B
INTA, INTB
TXRDYA, TXRDYB
RXRDYA, RXRDYB
INTERRUPT
CONTROL
LOGIC
CLOCK AND
BAUD RATE
GENERATOR
MODEM
CONTROL
LOGIC
CTSA, CTSB
RIA, RIB
CDA, CDB
DSRA, DSRB
002aaa592
XTAL1
XTAL2
Fig 1. Block diagram of SC16C652B
SC16C652B_4
Product data sheet
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Rev. 04 — 1 September 2005
3 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
5. Pinning information
37 n.c.
38 CTSA
39 DSRA
40 CDA
42 VCC
41 RIA
43 TXRDYA
44 D0
45 D1
46 D2
47 D3
48 D4
5.1 Pinning
D5
1
36 RESET
D6
2
35 DTRB
D7
3
34 DTRA
RXB
4
33 RTSA
RXA
5
32 OP2A
TXRDYB
6
TXA
7
TXB
8
29 INTB
OP2B
9
28 A0
CSA 10
27 A1
CSB 11
26 A2
n.c. 12
25 n.c.
31 RXRDYA
n.c. 24
CTSB 23
RIB 21
30 INTA
RTSB 22
DSRB 20
IOR 19
RXRDYB 18
GND 17
CDB 16
IOW 15
XTAL2 14
XTAL1 13
SC16C652BIB48
002aaa593
25 CTSA
26 VCC
27 D0
28 D1
29 D2
30 D3
32 D5
terminal 1
index area
31 D4
Fig 2. Pin configuration for LQFP48
D6
1
24 RESET
D7
2
23 RTSA
RXB
3
22 OP2A
RXA
4
TXA
5
TXB
6
19 A0
OP2B
7
18 A1
CSA
8
17 A2
21 INTA
20 INTB
CTSB 16
IOR 14
RTSB 15
GND 13
IOW 12
XTAL2 11
XTAL1 10
CSB
9
SC16C652BIBS
002aaa865
Transparent top view
Fig 3. Pin configuration for HVQFN32
SC16C652B_4
Product data sheet
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Rev. 04 — 1 September 2005
4 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
5.2 Pin description
Table 2:
Pin description
Symbol
Pin
Type Description
LQFP48 HVQFN32
A0
28
19
I
Address 0 select bit. Internal register address selection.
A1
27
18
I
Address 1 select bit. Internal register address selection.
A2
26
17
I
Address 2 select bit. Internal register address selection.
CDA
40
-
I
CDB
16
-
Carrier Detect (active LOW). These inputs are associated with individual UART
channels A through B. A logic 0 on this pin indicates that a carrier has been
detected by the modem for that channel.
CSA
10
8
I
CSB
11
9
Chip Select A, B (active LOW). This function is associated with individual
channels, A through B. These pins enable data transfers between the user CPU
and the SC16C652B for the channel(s) addressed. Individual UART sections (A, B)
are addressed by providing a logic 0 on the respective CSA, CSB pin.
CTSA
38
25
I
CTSB
23
16
Clear to Send (active LOW). These inputs are associated with individual UART
channels, A through B. A logic 0 on the CTS pin indicates the modem or data set is
ready to accept transmit data from the SC16C652B. Status can be tested by
reading MSR[4]. This pin has no effect on the UART’s transmit or receive
operation.
DSRA
39
-
I
DSRB
20
-
Data Set Ready (active LOW). These inputs are associated with individual UART
channels, A through B. A logic 0 on this pin indicates the modem or data set is
powered-on and is ready for data exchange with the UART. This pin has no effect
on the UART’s transmit or receive operation.
DTRA
34
-
O
DTRB
35
-
Data Terminal Ready (active LOW). These outputs are associated with individual
UART channels, A through B. A logic 0 on this pin indicates that the SC16C652B is
powered-on and ready. This pin can be controlled via the modem control register.
Writing a logic 1 to MCR[0] will set the DTR output to logic 0, enabling the modem.
This pin will be a logic 1 after writing a logic 0 to MCR[0], or after a reset. This pin
has no effect on the UART’s transmit or receive operation.
D0
44
27
I/O
D1
45
28
D2
46
29
Data bus (bi-directional). These pins are the 8-bit, 3-state data bus for
transferring information to or from the controlling CPU. D0 is the least significant bit
and the first data bit in a transmit or receive serial data stream.
D3
47
30
D4
48
31
D5
1
32
D6
2
1
D7
3
2
GND
17
13
I
Signal and power ground.
INTA
30
21
O
INTB
29
20
Interrupt A, B (3-state). This function is associated with individual channel
interrupts, INTA, INTB. INTA, INTB are enabled when MCR bit 3 is set to a logic 1,
interrupts are enabled in the Interrupt Enable Register (IER), and is active when an
interrupt condition exists. Interrupt conditions include: receiver errors, available
receiver buffer data, transmit buffer empty, or when a modem status flag is
detected.
IOR
19
14
I
Read strobe (active LOW strobe). A logic 0 transition on this pin will load the
contents of an internal register defined by address bits A0 to A2 onto the
SC16C652B data bus (D0 to D7) for access by external CPU.
SC16C652B_4
Product data sheet
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Rev. 04 — 1 September 2005
5 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
Table 2:
Pin description …continued
Symbol
Pin
Type Description
LQFP48 HVQFN32
IOW
15
12
I
Write strobe (active LOW strobe). A logic 0 transition on this pin will transfer the
contents of the data bus (D0 to D7) from the external CPU to an internal register
that is defined by address bits A0 to A2.
OP2A
32
22
O
OP2B
9
7
Output 2 (user-defined). This function is associated with individual channels, A
through B. The state at these pin(s) are defined by the user and through MCR
register bit 3. INTA, INTB are set to the active mode and OP2 to logic 0 when
MCR[3] is set to a logic 1. INTA, INTB are set to the 3-state mode and OP2 to a
logic 1 when MCR[3] is set to a logic 0 (see Table 20 “Modem Control Register bits
description”, bit 3). Since these bits control both the INTA, INTB operation and
OP2 outputs, only one function should be used at one time, INT or OP2.
RESET
36
24
I
Reset (active HIGH). A logic 1 on this pin will reset the internal registers and all
the outputs. The UART transmitter output and the receiver input will be disabled
during reset time. (See Section 7.11 “SC16C652B external reset condition” for
initialization details.)
RIA
41
-
I
RIB
21
-
Ring Indicator (active LOW). These inputs are associated with individual UART
channels, A through B. A logic 0 on this pin indicates the modem has received a
ringing signal from the telephone line. A logic 1 transition on this input pin will
generate an interrupt.
RTSA
33
23
O
RTSB
22
15
Request to Send (active LOW). These outputs are associated with individual
UART channels, A through B. A logic 0 on the RTS pin indicates the transmitter
has data ready and waiting to send. Writing a logic 1 in the modem control register
MCR[1] will set this pin to a logic 0, indicating data is available. After a reset this
pin will be set to a logic 1. This pin has no effect on the UART’s transmit or receive
operation.
RXA
5
4
I
RXB
4
3
Receive data A, B. These inputs are associated with individual serial channel data
to the SC16C652B receive input circuits, A through B. The RX signal will be a
logic 1 during reset, idle (no data), or when the transmitter is disabled. During the
local loop-back mode, the RX input pin is disabled and TX data is connected to the
UART RX input, internally.
RXRDYA
31
-
O
RXRDYB 18
-
Receive Ready A, B (active LOW). This function provides the RX FIFO/RHR
status for individual receive channels (A to B). RXRDYn is primarily intended for
monitoring DMA mode 1 transfers for the receive data FIFOs. A logic 0 indicates
there is a receive data to read/upload, that is, receive ready status with one or
more RX characters available in the FIFO/RHR. This pin is a logic 1 when the
FIFO/RHR is empty or when the programmed trigger level has not been reached.
This signal can also be used for single mode transfers (DMA mode 0).
TXA
7
5
O
TXB
8
6
Transmit data A, B. These outputs are associated with individual serial transmit
channel data from the SC16C652B. The TX signal will be a logic 1 during reset,
idle (no data), or when the transmitter is disabled. During the local loop-back
mode, the TX output pin is disabled and TX data is internally connected to the
UART RX input.
TXRDYA
43
-
O
TXRDYB
6
-
Transmit Ready A, B (active LOW). These outputs provide the TX FIFO/THR
status for individual transmit channels (A to B). TXRDYn is primarily intended for
monitoring DMA mode 1 transfers for the transmit data FIFOs. An individual
channel’s TXRDYA, TXRDYB buffer ready status is indicated by logic 0, that is, at
lease one location is empty and available in the FIFO or THR. This pin goes to a
logic 1 (DMA mode 1) when there are no more empty locations in the FIFO or
THR. This signal can also be used for single mode transfers (DMA mode 0).
SC16C652B_4
Product data sheet
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Rev. 04 — 1 September 2005
6 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
Table 2:
Pin description …continued
Symbol
Pin
Type Description
LQFP48 HVQFN32
VCC
42
26
I
Power supply input.
XTAL1
13
10
I
Crystal or external clock input. Functions as a crystal input or as an external
clock input. A crystal can be connected between this pin and XTAL2 to form an
internal oscillator circuit. This configuration requires an external 1 MΩ resistor
between the XTAL1 and XTAL2 pins. Alternatively, an external clock can be
connected to this pin to provide custom data rates (see Section 6.8
“Programmable baud rate generator”). See Figure 4.
XTAL2
14
11
O
Output of the crystal oscillator or buffered clock. (See also XTAL1.) Crystal
oscillator output or buffered clock output. Should be left open if an external clock is
connected to XTAL1. For extended frequency operation, this pin should be tied to
VCC via a 2 kΩ resistor.
6. Functional description
The SC16C652B provides serial asynchronous receive data synchronization,
parallel-to-serial and serial-to-parallel data conversions for both the transmitter and
receiver sections. These functions are necessary for converting the serial data stream into
parallel data that is required with digital data systems. Synchronization for the serial data
stream is accomplished by adding start and stop bits to the transmit data to form a data
character (character orientated protocol). Data integrity is insured by attaching a parity bit
to the data character. The parity bit is checked by the receiver for any transmission bit
errors. The electronic circuitry to provide all these functions is fairly complex, especially
when manufactured on a single integrated silicon chip. The SC16C652B represents such
an integration with greatly enhanced features. The SC16C652B is fabricated with an
advanced CMOS process.
The SC16C652B is an upward solution that provides a dual UART capability with 32 bytes
of transmit and receive FIFO memory, instead of 16 bytes for the 16C2550 and none in
the 16C2450. The SC16C652B is designed to work with high speed modems and shared
network environments that require fast data processing time. Increased performance is
realized in the SC16C652B by the transmit and receive FIFOs. This allows the external
processor to handle more networking tasks within a given time. In addition, the four
selectable receive and transmit FIFO trigger interrupt levels are uniquely provided for
maximum data throughput performance especially when operating in a multi-channel
environment. The FIFO memory greatly reduces the bandwidth requirement of the
external controlling CPU, increases performance, and reduces power consumption.
The SC16C652B is capable of operation up to 5 Mbit/s with a 80 MHz clock. With a crystal
or external clock input of 7.3728 MHz, the user can select data rates up to 460.8 kbit/s.
The rich feature set of the SC16C652B is available through internal registers. Selectable
receive and transmit FIFO trigger levels, selectable TX and RX baud rates, and modem
interface controls are all standard features. Following a power-on reset or an external
reset, the SC16C652B is software compatible with the previous generation, SC16C2550
and ST16C2450.
SC16C652B_4
Product data sheet
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Rev. 04 — 1 September 2005
7 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
6.1 UART A-B functions
The UART provides the user with the capability to bi-directionally transfer information
between an external CPU, the SC16C652B package, and an external serial device. A
logic 0 on chip select pins CSA and/or CSB allows the user to configure, send data,
and/or receive data via UART channels A-B. Individual channel select functions are shown
in Table 3.
Table 3:
Serial port selection
Chip Select
Function
CSA-CSB = 1
none
CSA = 0
UART channel A
CSB = 0
UART channel B
6.2 Internal registers
The SC16C652B provides two sets of internal registers (A and B) consisting of
17 registers each for monitoring and controlling the functions of each channel of the
UART. These registers are shown in Table 4. The UART registers function as data holding
registers (THR/RHR), interrupt status and control registers (IER/ISR), a FIFO Control
Register (FCR), line status and control registers (LCR/LSR), modem status and control
registers (MCR/MSR), programmable data rate (clock) control registers (DLL/DLM), and a
user accessible Scratchpad Register (SPR).
Table 4:
A2
Internal registers decoding
A1
A0
Read mode
Write mode
General register set (THR/RHR, IER/ISR, MCR/MSR, FCR, LSR, SPR) [1]
0
0
0
Receive Holding Register
Transmit Holding Register
0
0
1
Interrupt Enable Register
Interrupt Enable Register
0
1
0
Interrupt Status Register
FIFO Control Register
0
1
1
Line Control Register
Line Control Register
1
0
0
Modem Control Register
Modem Control Register
1
0
1
Line Status Register
n/a
1
1
0
Modem Status Register
n/a
1
1
1
Scratchpad Register
Scratchpad Register
Baud rate register set
(DLL/DLM) [2]
0
0
0
LSB of Divisor Latch
LSB of Divisor Latch
0
0
1
MSB of Divisor Latch
MSB of Divisor Latch
Enhanced register set (EFR, Xon1/Xon2,
Xoff1/Xoff2) [3]
0
1
0
Enhanced Feature Register
Enhanced Feature Register
1
0
0
Xon1 word
Xon1 word
1
0
1
Xon2 word
Xon2 word
1
1
0
Xoff1 word
Xoff1 word
1
1
1
Xoff2 word
Xoff2 word
[1]
These registers are accessible only when LCR[7] is a logic 0.
[2]
These registers are accessible only when LCR[7] is a logic 1.
[3]
Enhanced Feature Register, Xon1/Xon2 and Xoff1/Xoff2 are accessible only when the LCR is set to ‘BFh’.
SC16C652B_4
Product data sheet
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Rev. 04 — 1 September 2005
8 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
6.3 FIFO operation
The 32-byte transmit and receive data FIFOs are enabled by the FIFO Control Register
bit 0 (FCR[0]). With 16C2550 devices, the user can set the receive trigger level, but not
the transmit trigger level. The SC16C652B provides independent trigger levels for both
receiver and transmitter. To remain compatible with SC16C2550, the transmit interrupt
trigger level is set to 16 following a reset. It should be noted that the user can set the
transmit trigger levels by writing to the FCR, but activation will not take place until EFR[4]
is set to a logic 1. The receiver FIFO section includes a time-out function to ensure data is
delivered to the external CPU. An interrupt is generated whenever the Receive Holding
Register (RHR) has not been read following the loading of a character or the receive
trigger level has not been reached.
Table 5:
Flow control mechanism
Selected trigger level
(characters)
INT pin activation
TX
Negate RTS or
send Xoff
Assert RTS or
send Xon
RX
8
8
16
8
0
16
16
8
16
7
24
24
24
24
15
28
28
30
28
23
6.4 Hardware flow control
When automatic hardware flow control is enabled, the SC16C652B monitors the CTS pin
for a remote buffer overflow indication and controls the RTS pin for local buffer overflows.
Automatic hardware flow control is selected by setting EFR[6] (RTS) and EFR[7] (CTS) to
a logic 1. If CTS transitions from a logic 0 to a logic 1 indicating a flow control request,
ISR[5] will be set to a logic 1 (if enabled via IER[7:6]), and the SC16C652B will suspend
TX transmissions as soon as the stop bit of the character in process is shifted out.
Transmission is resumed after the CTS input returns to a logic 0, indicating more data may
be sent.
With the Auto-RTS function enabled, an interrupt is generated when the receive FIFO
reaches the programmed trigger level. The RTS pin will not be forced to a logic 1 (RTS
off), until the receive FIFO reaches the next trigger level. However, the RTS pin will return
to a logic 0 after the data buffer (FIFO) is unloaded to the next trigger level below the
programmed trigger level. However, under the above described conditions, the
SC16C652B will continue to accept data until the receive FIFO is full.
6.5 Software flow control
When software flow control is enabled, the SC16C652B compares one or two sequential
receive data characters with the programmed Xon or Xoff character value(s). If received
character(s) match the programmed Xoff values, the SC16C652B will halt transmission
(TX) as soon as the current character(s) has completed transmission. When a match
occurs, the receive ready (if enabled via Xoff IER[5]) flags will be set and the interrupt
output pin (if receive interrupt is enabled) will be activated. Following a suspension due to
a match of the Xoff characters’ values, the SC16C652B will monitor the receive data
stream for a match to the Xon1/Xon2 character value(s). If a match is found, the
SC16C652B will resume operation and clear the flags (ISR[4]).
SC16C652B_4
Product data sheet
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Rev. 04 — 1 September 2005
9 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
Reset initially sets the contents of the Xon/Xoff 8-bit flow control registers to a logic 0.
Following reset, the user can write any Xon/Xoff value desired for software flow control.
Different conditions can be set to detect Xon/Xoff characters and suspend/resume
transmissions. When double 8-bit Xon/Xoff characters are selected, the SC16C652B
compares two consecutive receive characters with two software flow control 8-bit values
(Xon1, Xon2, Xoff1, Xoff2) and controls TX transmissions accordingly. Under the above
described flow control mechanisms, flow control characters are not placed (stacked) in the
user accessible RX data buffer or FIFO. When using a software flow control the Xon/Xoff
characters cannot be used for data transfer.
In the event that the receive buffer is overfilling and flow control needs to be executed, the
SC16C652B automatically sends an Xoff message (when enabled) via the serial TX
output to the remote modem. The SC16C652B sends the Xoff1/Xoff2 characters as soon
as received data passes the programmed trigger level. To clear this condition, the
SC16C652B will transmit the programmed Xon1/Xon2 characters as soon as receive data
drops below the programmed trigger level.
6.6 Special feature software flow control
A special feature is provided to detect an 8-bit character when EFR[5] is set. When 8-bit
character is detected, it will be placed on the user-accessible data stack along with normal
incoming RX data. This condition is selected in conjunction with EFR[3:0]. Note that
software flow control should be turned off when using this special mode by setting
EFR[3:0] to a logic 0.
The SC16C652B compares each incoming receive character with Xoff2 data. If a match
exists, the received data will be transferred to the FIFO, and ISR[4] will be set to indicate
detection of a special character. Although Table 9 “SC16C652B internal registers” shows
each X-Register with eight bits of character information, the actual number of bits is
dependent on the programmed word length. Line Control Register bits LCR[1:0] define the
number of character bits, that is, either 5 bits, 6 bits, 7 bits or 8 bits. The word length
selected by LCR[1:0] also determine the number of bits that will be used for the special
character comparison. Bit 0 in the X-registers corresponds with the LSB bit for the receive
character.
6.7 Hardware/software and time-out interrupts
The interrupts are enabled by IER[3:0]. Care must be taken when handling these
interrupts. Following a reset, if Interrupt Enable Register (IER) bit 1 = 1, the SC16C652B
will issue a Transmit Holding Register interrupt. This interrupt must be serviced prior to
continuing operations. The ISR provides the current singular highest priority interrupt only.
It could be noted that CTS and RTS interrupts have lowest interrupt priority. A condition
can exist where a higher priority interrupt may mask the lower priority CTS/RTS
interrupt(s). Only after servicing the higher pending interrupt will the lower priority
CTS/RTS interrupt(s) be reflected in the status register. Servicing the interrupt without
investigating further interrupt conditions can result in data errors.
When two interrupt conditions have the same priority, it is important to service these
interrupts correctly. Receive Data Ready and Receive Time Out have the same interrupt
priority (when enabled by IER[0]). The receiver issues an interrupt after the number of
characters have reached the programmed trigger level. In this case, the SC16C652B
FIFO may hold more characters than the programmed trigger level. Following the removal
of a data byte, the user should re-check LSR[0] for additional characters. A Receive
SC16C652B_4
Product data sheet
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Rev. 04 — 1 September 2005
10 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
Time Out will not occur if the receive FIFO is empty. The time-out counter is reset at the
center of each stop bit received or each time the Receive Holding Register (RHR) is read.
The actual time-out value is 4 character time, including data information length, start bit,
parity bit, and the size of stop bit, that is, 1×, 1.5×, or 2× bit times.
6.8 Programmable baud rate generator
The SC16C652B supports high speed modem technologies that have increased input
data rates by employing data compression schemes. For example, a 33.6 kbit/s modem
that employs data compression may require a 115.2 kbit/s input data rate. A 128.0 kbit/s
ISDN modem that supports data compression may need an input data rate of 460.8 kbit/s.
The SC16C652B can support a standard data rate of 921.6 kbit/s.
A single baud rate generator is provided for the transmitter and receiver, allowing
independent TX/RX channel control. The programmable Baud Rate Generator is capable
of operating with a frequency of up to 80 MHz. To obtain maximum data rate, it is
necessary to use full rail swing on the clock input. The SC16C652B can be configured for
internal or external clock operation. For internal clock oscillator operation, an industry
standard microprocessor crystal is connected externally between the XTAL1 and XTAL2
pins. Alternatively, an external clock can be connected to the XTAL1 pin to clock the
internal baud rate generator for standard or custom rates (see Table 6).
The generator divides the input 16× clock by any divisor from 1 to (216 − 1). The
SC16C652B divides the basic external clock by 16. The basic 16× clock provides table
rates to support standard and custom applications using the same system design. The
rate table is configured via the DLL and DLM internal register functions. Customized baud
rates can be achieved by selecting the proper divisor values for the MSB and LSB
sections of baud rate generator.
Programming the baud rate generator registers DLM (MSB) and DLL (LSB) provides a
user capability for selecting the desired final baud rate. The example in Table 6 shows the
selectable baud rate table available when using a 1.8432 MHz external clock input.
XTAL1
XTAL2
X1
1.8432 MHz
C1
22 pF
XTAL1
XTAL2
X1
1.8432 MHz
C2
33 pF
C1
22 pF
1.5 kΩ
C2
47 pF
002aaa870
Fig 4. Crystal oscillator connection
SC16C652B_4
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SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
Table 6:
Baud rate generator programming table using a 1.8432 MHz clock
Output
baud rate
(bit/s)
Output
16× clock divisor
(decimal)
Output
16× clock divisor
(HEX)
DLM
program value
(HEX)
DLL
program value
(HEX)
50
2304
900
09
00
75
1536
600
06
00
110
1047
417
04
17
150
768
300
03
00
300
384
180
01
80
600
192
C0
00
C0
1200
96
60
00
60
2400
48
30
00
30
3600
32
20
00
20
4800
24
18
00
18
7200
16
10
00
10
9600
12
0C
00
0C
19.2 k
6
06
00
06
38.4 k
3
03
00
03
57.6 k
2
02
00
02
115.2 k
1
01
00
01
6.9 DMA operation
The SC16C652B FIFO trigger level provides additional flexibility to the user for block
mode operation. The user can optionally operate the transmit and receive FIFOs in the
DMA mode (FCR[3]). The DMA mode affects the state of the RXRDY and TXRDY output
pins. Table 7 and Table 8 show this.
Table 7:
Effect of DMA mode on state of RXRDY pin
Non-DMA mode
DMA mode
1 = FIFO empty
0-to-1 transition when FIFO empties
0 = at least 1 byte in FIFO
1-to-0 transition when FIFO reaches trigger level, or time-out occurs
Table 8:
Effect of DMA mode on state of TXRDY pin
Non-DMA mode
DMA mode
1 = at least 1 byte in FIFO
0-to-1 transition when FIFO becomes full
0 = FIFO empty
1-to-0 transition when FIFO goes below trigger level
6.10 Loop-back mode
The internal loop-back capability allows on-board diagnostics. In the loop-back mode, the
normal modem interface pins are disconnected and reconfigured for loop-back internally
(see Figure 5). MCR[3:0] register bits are used for controlling loop-back diagnostic testing.
In the loop-back mode, the transmitter output (TX) and the receiver input (RX) are
disconnected from their associated interface pins, and instead are connected together
internally. The CTS, DSR, CD, and RI are disconnected from their normal modem control
inputs pins, and instead are connected internally to RTS, DTR, MCR[3] (OP2) and
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Dual UART with 32-byte FIFOs and IrDA encoder/decoder
MCR[2] (OP1). Loop-back test data is entered into the transmit holding register via the
user data bus interface, D[7:0]. The transmit UART serializes the data and passes the
serial data to the receive UART via the internal loop-back connection. The receive UART
converts the serial data back into parallel data that is then made available at the user data
interface D[7:0]. The user optionally compares the received data to the initial transmitted
data for verifying error-free operation of the UART TX/RX circuits.
In this mode, the receiver and transmitter interrupts are fully operational. The modem
control interrupts are also operational.
SC16C652B
D0 to D7
IOR
IOW
RESET
TXA, TXB
DATA BUS
AND
CONTROL
LOGIC
REGISTER
SELECT
LOGIC
INTERCONNECT BUS LINES
AND
CONTROL SIGNALS
FLOW
CONTROL
LOGIC
A0 to A2
CSA
CSB
TRANSMIT
SHIFT
REGISTER
RECEIVE
FIFO
REGISTERS
FLOW
CONTROL
LOGIC
IR
ENCODER
MCR[4] = 1
TRANSMIT
FIFO
REGISTERS
RECEIVE
SHIFT
REGISTER
RXA, RXB
IR
DECODER
RTSA, RTSB
CTSA, CTSB
DTRA, DTRB
MODEM
CONTROL
LOGIC
INTA, INTB
TXRDYA, TXRDYB
RXRDYA, RXRDYB
INTERRUPT
CONTROL
LOGIC
DSRA, DSRB
(OP1A, OP1B)
CLOCK AND
BAUD RATE
GENERATOR
RIA, RIB
(OP2A, OP2B)
CDA, CDB
002aaa594
XTAL1 XTAL2
Fig 5. Internal loop-back mode diagram
SC16C652B_4
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SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
6.11 Sleep mode
Sleep mode is an enhanced feature of the SC16C652B UART. It is enabled when EFR[4],
the enhanced functions bit, is set and when IER[4] of both channels are set. Sleep mode
is entered when:
•
•
•
•
Modem input pins are not toggling.
The serial data input line, RX, is idle (logic HIGH).
The TX FIFO and TX shift register are empty.
There are no interrupts pending.
Remark: Sleep mode will not be entered if there is data in the RX FIFO.
In Sleep mode, the UART clock and baud rate clock are stopped. Since most registers are
clocked using these clocks, the power consumption is greatly reduced.
Remark: Writing to the divisor latches, DLL and DLH, to set the baud clock, must not be
done during Sleep mode. Therefore, it is advisable to disable Sleep mode using IER[4]
before writing to DLL or DLH.
SC16C652B resumes normal operation by any of the following:
• Receives a start bit on RXA/RXB pin.
• Data is loaded into transmit FIFO.
• A change of state on any of the modem input pins
If the device is awakened by one of the conditions described above, it will return to the
Sleep mode automatically after the last character is transmitted or read by the user. The
device will stay in Sleep mode until it is disabled by setting any channel’s IER bit 4 to a
logic 0.
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SC16C652B
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Dual UART with 32-byte FIFOs and IrDA encoder/decoder
7. Register descriptions
Table 9 details the assigned bit functions for the SC16C652B internal registers. The
assigned bit functions are more fully defined in Section 7.1 through Section 7.11.
Table 9:
SC16C652B internal registers
A2 A1 A0 Register Default [1] Bit 7
General Register
0
0
0
RHR
0
0
0
0
0
1
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Set [3]
XX
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
THR
XX
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
IER
00
CTS
interrupt
RTS
interrupt
Xoff
interrupt
Sleep
mode [2]
[2]
[2]
[2]
modem
status
interrupt
Rx
receive
line
status
interrupt
transmit
holding
register
interrupt
receive
holding
register
0
1
0
FCR
00
RCVR
trigger
(MSB)
RCVR
trigger
(LSB)
TX
trigger
(MSB) [2]
TX trigger DMA
(LSB) [2]
mode
select
XMIT
FIFO
reset
RCVR
FIFO
reset
FIFOs
enable
0
1
0
ISR
01
FIFOs
enabled
FIFOs
enabled
INT
priority
bit 4
INT
priority
bit 3
INT
priority
bit 2
INT
priority
bit 1
INT
priority
bit 0
INT
status
0
1
1
LCR
00
divisor
latch
enable
set break set parity even
parity
parity
enable
stop bits
word
length
bit 1
word
length
bit 0
1
0
0
MCR
00
clock
select [2]
IRDA
enable
loop back OP2/INT (OP1)
enable
RTS
DTR
1
0
1
LSR
60
FIFO
data
error
THR and THR
TSR
empty
empty
break
interrupt
framing
error
parity
error
overrun
error
receive
data
ready
1
1
0
MSR
X0
CD
RI
DSR
CTS
∆CD
∆RI
∆DSR
∆CTS
1
1
1
SPR
FF
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
0
Special Register Set [4]
0
0
0
DLL
XX
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
0
0
1
DLM
XX
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
Enhanced Register
Set [5]
0
1
0
EFR
00
Auto
CTS
Cont-3
Auto RTS special
Enable
character IER[7:4], Tx, Rx
select
ISR[5:4], Control
FCR[5:4],
MCR[7:5]
Cont-2
Tx, Rx
Control
Cont-1
Tx, Rx
Control
Cont-0
Tx, Rx
Control
1
0
0
Xon-1
00
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
1
0
1
Xon-2
00
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
1
1
0
Xoff-1
00
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
1
1
1
Xoff-2
00
bit 15
bit 14
bit 13
bit 12
bit 11
bit 10
bit 9
bit 8
[1]
The value shown in represents the register’s initialized HEX value; X = not applicable.
[2]
This bit is only accessible when EFR[4] is set.
[3]
Accessible only when LCR[7] is logic 0.
[4]
Baud rate registers accessible only when LCR[7] is logic 1.
[5]
Enhanced Feature Register, Xon1/Xon2 and Xoff1/Xoff2 are accessible only when LCR is set to ‘BFh’.
SC16C652B_4
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SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
7.1 Transmit (THR) and Receive (RHR) Holding Registers
The serial transmitter section consists of an 8-bit Transmit Hold Register (THR) and
Transmit Shift Register (TSR). The status of the THR is provided in the Line Status
Register (LSR). Writing to the THR transfers the contents of the data bus (D7 to D0) to the
TSR and UART via the THR, providing that the THR is empty. The THR empty flag in the
LSR will be set to a logic 1 when the transmitter is empty or when data is transferred to the
TSR. Note that a write operation can be performed when the THR empty flag is set
(logic 0 = at least one byte in FIFO/THR, logic 1 = FIFO/THR empty).
The serial receive section also contains an 8-bit Receive Holding Register (RHR) and a
Receive Serial Shift Register (RSR). Receive data is removed from the SC16C652B and
receive FIFO by reading the RHR. The receive section provides a mechanism to prevent
false starts. On the falling edge of a start or false start bit, an internal receiver counter
starts counting clocks at the 16× clock rate. After 71⁄2 clocks, the start bit time should be
shifted to the center of the start bit. At this time the start bit is sampled, and if it is still a
logic 0 it is validated. Evaluating the start bit in this manner prevents the receiver from
assembling a false character. Receiver status codes will be posted in the LSR.
7.2 Interrupt Enable Register (IER)
The Interrupt Enable Register (IER) masks the interrupts from receiver ready, transmitter
empty, line status and modem status registers. These interrupts would normally be seen
on the INTA, INTB output pins.
Table 10:
Interrupt Enable Register bits description
Bit
Symbol Description
7
IER[7]
CTS interrupt.
logic 0 = disable the CTS interrupt (normal default condition)
logic 1 = enable the CTS interrupt. The SC16C652B issues an interrupt when
the CTS pin transitions from a logic 0 to a logic 1.
6
IER[6]
RTS interrupt.
logic 0 = disable the RTS interrupt (normal default condition)
logic 1 = enable the RTS interrupt. The SC16C652B issues an interrupt when
the RTS pin transitions from a logic 0 to a logic 1.
5
IER[5]
Xoff interrupt.
logic 0 = disable the software flow control, receive Xoff interrupt (normal
default condition)
logic 1 = enable the software flow control, receive Xoff interrupt.
4
IER[4]
Sleep mode.
logic 0 = disable Sleep mode (normal default condition)
logic 1 = enable Sleep mode
3
IER[3]
Modem Status Interrupt. This interrupt will be issued whenever there is a modem
status change as reflected in MSR[3:0].
logic 0 = disable the modem status register interrupt (normal default condition)
logic 1 = enable the modem status register interrupt
2
IER[2]
Receive Line Status interrupt. This interrupt will be issued whenever a receive
data error condition exists as reflected in LSR[4:1].
logic 0 = disable the receiver line status interrupt (normal default condition)
logic 1 = enable the receiver line status interrupt
SC16C652B_4
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SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
Table 10:
Interrupt Enable Register bits description …continued
Bit
Symbol Description
1
IER[1]
Transmit Holding Register interrupt. In the 16C450 mode, this interrupt will be
issued whenever the THR is empty, and is associated with LSR[5]. In the FIFO
modes, this interrupt will be issued whenever the FIFO is empty.
logic 0 = disable the Transmit Holding Register Empty (TXRDY) interrupt
(normal default condition)
logic 1 = enable the TXRDY (ISR level 3) interrupt
0
IER[0]
Receive Holding Register. In the 16C450 mode, this interrupt will be issued when
the RHR has data, or is cleared when the RHR is empty. In the FIFO mode, this
interrupt will be issued when the FIFO has reached the programmed trigger level
or is cleared when the FIFO drops below the trigger level.
logic 0 = disable the receiver ready (ISR level 2, RXRDY) interrupt (normal
default condition)
logic 1 = enable the RXRDY (ISR level 2) interrupt
7.2.1 IER versus Transmit/Receive FIFO interrupt mode operation
When the receive FIFO (FCR[0] = logic 1), and receive interrupts (IER[0] = logic 1) are
enabled, the receive interrupts and register status will reflect the following:
• The receive RXRDY interrupt (Level 2 ISR interrupt) is issued to the external CPU
when the receive FIFO has reached the programmed trigger level. It will be cleared
when the receive FIFO drops below the programmed trigger level.
• Receive FIFO status will also be reflected in the user accessible ISR register when
the receive FIFO trigger level is reached. Both the ISR register receive status bit and
the interrupt will be cleared when the FIFO drops below the trigger level.
• The receive data ready bit (LSR[0]) is set as soon as a character is transferred from
the shift register (RSR) to the receive FIFO. It is reset when the FIFO is empty.
• When the Transmit FIFO and interrupts are enabled, an interrupt is generated when
the transmit FIFO is empty due to the unloading of the data by the TSR and UART for
transmission via the transmission media. The interrupt is cleared either by reading the
ISR, or by loading the THR with new data characters.
7.2.2 IER versus Receive/Transmit FIFO polled mode operation
When FCR[0] = logic 1, resetting IER[3:0] enables the SC16C652B in the FIFO polled
mode of operation. In this mode, interrupts are not generated and the user must poll the
LSR register for TX and/or RX data status. Since the receiver and transmitter have
separate bits in the LSR either or both can be used in the polled mode by selecting
respective transmit or receive control bit(s).
•
•
•
•
•
LSR[0] will be a logic 1 as long as there is one byte in the receive FIFO.
LSR[4:1] will provide the type of receive errors, or a receive break, if encountered.
LSR[5] will indicate when the transmit FIFO is empty.
LSR[6] will indicate when both the transmit FIFO and transmit shift register are empty.
LSR[7] will show if any FIFO data errors occurred.
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Dual UART with 32-byte FIFOs and IrDA encoder/decoder
7.3 FIFO Control Register (FCR)
This register is used to enable the FIFOs, clear the FIFOs, set the receive FIFO trigger
levels, and select the DMA mode.
7.3.1 DMA mode
7.3.1.1
Mode 0 (FCR bit 3 = 0)
Set and enable the interrupt for each single transmit or receive operation, and is similar to
the 16C450 mode. Transmit Ready (TXRDY) will go to a logic 0 whenever the FIFO (THR,
if FIFO is not enabled) is empty. Receive Ready (RXRDY) will go to a logic 0 whenever the
Receive Holding Register (RHR) is loaded with a character.
7.3.1.2
Mode 1 (FCR bit 3 = 1)
Set and enable the interrupt in a block mode operation. The transmit interrupt is set when
the transmit FIFO is below the programmed trigger level. The receive interrupt is set when
the receive FIFO fills to the programmed trigger level. However, the FIFO continues to fill
regardless of the programmed level until the FIFO is full. RXRDY remains a logic 0 as long
as the FIFO fill level is above the programmed trigger level.
7.3.2 FIFO mode
Table 11:
FIFO Control Register bits description
Bit
Symbol
Description
7:6
FCR[7:6]
RCVR trigger. These bits are used to set the trigger level for the receive FIFO
interrupt.
An interrupt is generated when the number of characters in the FIFO equals
the programmed trigger level. However, the FIFO will continue to be loaded
until it is full. Refer to Table 12.
5:4
FCR[5:4]
Logic 0 or cleared is the default condition; TX trigger level = 16.
These bits are used to set the trigger level for the transmit FIFO interrupt.
The SC16C652B will issue a transmit empty interrupt when the number of
characters in FIFO drops below the selected trigger level. Refer to Table 13.
3
FCR[3]
DMA mode select.
logic 0 = set DMA mode ‘0’ (normal default condition)
logic 1 = set DMA mode ‘1’
Transmit operation in mode ‘0’: When the SC16C652B is in the 16C450
mode (FIFOs disabled; FCR[0] = logic 0) or in the FIFO mode (FIFOs
enabled; FCR[0] = logic 1; FCR[3] = logic 0), and when there are no
characters in the transmit FIFO or transmit holding register, the TXRDY pin
will be a logic 0. Once active, the TXRDY pin will go to a logic 1 after the first
character is loaded into the transmit holding register.
Receive operation in mode ‘0’: When the SC16C652B is in 16C450 mode,
or in the FIFO mode (FCR[0] = logic 1; FCR[3] = logic 0) and there is at least
one character in the receive FIFO, the RXRDY pin will be a logic 0. Once
active, the RXRDY pin will go to a logic 1 when there are no more characters
in the receiver.
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Dual UART with 32-byte FIFOs and IrDA encoder/decoder
Table 11:
Bit
FIFO Control Register bits description …continued
Symbol
3
(cont.)
Description
Transmit operation in mode ‘1’: When the SC16C652B is in FIFO mode
(FCR[0] = logic 1; FCR[3] = logic 1), the TXRDY pin will be a logic 1 when the
transmit FIFO is completely full. It will be a logic 0 when the trigger level has
been reached.
Receive operation in mode ‘1’: When the SC16C652B is in FIFO mode
(FCR[0] = logic 1; FCR[3] = logic 1) and the trigger level has been reached,
or a Receive Time-Out has occurred, the RXRDY pin will go to a logic 0.
Once activated, it will go to a logic 1 after there are no more characters in the
FIFO.
2
FCR[2]
XMIT FIFO reset.
logic 0 = no FIFO transmit reset (normal default condition)
logic 1 = clears the contents of the transmit FIFO and resets the FIFO
counter logic (the transmit shift register is not cleared or altered). This bit
will return to a logic 0 after clearing the FIFO.
1
FCR[1]
RCVR FIFO reset.
logic 0 = no FIFO receive reset (normal default condition)
logic 1 = clears the contents of the receive FIFO and resets the FIFO
counter logic (the receive shift register is not cleared or altered). This bit
will return to a logic 0 after clearing the FIFO.
0
FCR[0]
FIFO enable.
logic 0 = disable the transmit and receive FIFO (normal default condition)
logic 1 = enable the transmit and receive FIFO. This bit must be a ‘1’
when other FCR bits are written to, or they will not be programmed.
Table 12:
RCVR trigger levels
FCR[7]
FCR[6]
RX FIFO trigger level (bytes)
0
0
8
0
1
16
1
0
24
1
1
28
Table 13:
TX FIFO trigger levels
FCR[5]
FCR[4]
TX FIFO trigger level (bytes)
0
0
16
0
1
8
1
0
24
1
1
30
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SC16C652B
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Dual UART with 32-byte FIFOs and IrDA encoder/decoder
7.4 Interrupt Status Register (ISR)
The SC16C652B provides six levels of prioritized interrupts to minimize external software
interaction. The Interrupt Status Register (ISR) provides the user with six interrupt status
bits. Performing a read cycle on the ISR will provide the user with the highest pending
interrupt level to be serviced. No other interrupts are acknowledged until the pending
interrupt is serviced. A lower level interrupt may be seen after servicing the higher level
interrupt and re-reading the interrupt status bits. Table 14 “Interrupt source” shows the
data values (bits 5:0) for the six prioritized interrupt levels and the interrupt sources
associated with each of these interrupt levels.
Table 14:
Interrupt source
Priority ISR[5]
level
ISR[4]
ISR[3]
ISR[2]
ISR[1]
ISR[0]
Source of the interrupt
1
0
0
0
1
1
0
LSR (Receiver Line Status
Register)
2
0
0
0
1
0
0
RXRDY (Received Data Ready)
2
0
0
1
1
0
0
RXRDY (Receive Data time-out)
3
0
0
0
0
1
0
TXRDY (Transmitter Holding
Register Empty)
4
0
0
0
0
0
0
MSR (Modem Status Register)
5
0
1
0
0
0
0
RXRDY (Received Xoff signal)/
Special character
6
1
0
0
0
0
0
CTS, RTS change of state
Table 15:
Interrupt Status Register bits description
Bit
Symbol
Description
7:6
ISR[7:6]
FIFOs enabled. These bits are set to a logic 0 when the FIFOs are not being
used in the 16C450 mode. They are set to a logic 1 when the FIFOs are
enabled in the SC16C652B mode.
logic 0 or cleared = default condition
5:4
ISR[5:4]
INT priority bits 4:3. These bits are enabled when EFR[4] is set to a logic 1.
ISR[4] indicates that matching Xoff character(s) have been detected. ISR[5]
indicates that CTS, RTS have been generated. Note that once set to a
logic 1, the ISR[4] bit will stay a logic 1 until Xon character(s) are received.
3:1
ISR[3:1]
INT priority bits 2:0. These bits indicate the source for a pending interrupt at
interrupt priority levels 1, 2, and 3 (see Table 14).
0
ISR[0]
INT status.
logic 0 or cleared = default condition
logic 0 or cleared = default condition
logic 0 = an interrupt is pending and the ISR contents may be used as a
pointer to the appropriate interrupt service routine
logic 1 = no interrupt pending (normal default condition)
SC16C652B_4
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SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
7.5 Line Control Register (LCR)
The Line Control Register is used to specify the asynchronous data communication
format. The word length, the number of stop bits, and the parity are selected by writing the
appropriate bits in this register.
Table 16:
Line Control Register bits description
Bit
Symbol
Description
7
LCR[7]
Divisor latch enable. The internal baud rate counter latch and Enhanced
Feature mode enable.
logic 0 = divisor latch disabled (normal default condition)
logic 1 = divisor latch enabled
6
LCR[6]
Set break. When enabled, the Break control bit causes a break condition to
be transmitted (the TX output is forced to a logic 0 state). This condition
exists until disabled by setting LCR[6] to a logic 0.
logic 0 = no TX break condition (normal default condition)
logic 1 = forces the transmitter output (TX) to a logic 0 for alerting the
remote receiver to a line break condition
5:3
LCR[5:3]
Programs the parity conditions (see Table 17).
2
LCR[2]
Stop bits. The length of stop bit is specified by this bit in conjunction with the
programmed word length (see Table 18).
logic 0 or cleared = default condition
1:0
LCR[1:0]
Word length bits 1, 0. These two bits specify the word length to be
transmitted or received (see Table 19).
logic 0 or cleared = default condition
Table 17:
LCR[5:3] parity selection
LCR[5]
LCR[4]
LCR[3]
Parity selection
X
X
0
no parity
X
0
1
odd parity
0
1
1
even parity
0
0
1
forced parity ‘1’
1
1
1
forced parity ‘0’
Table 18:
LCR[2] stop bit length
LCR[2]
Word length (bits) Stop bit length (bit times)
0
5, 6, 7, 8
1
1
5
11⁄2
1
6, 7, 8
2
Table 19:
LCR[1:0] word length
LCR[1]
LCR[0]
Word length (bits)
0
0
5
0
1
6
1
0
7
1
1
8
SC16C652B_4
Product data sheet
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SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
7.6 Modem Control Register (MCR)
This register controls the interface with the modem or a peripheral device.
Table 20:
Modem Control Register bits description
Bit
Symbol
Description
7
MCR[7]
Clock select
logic 0 = divide-by-1 clock input
logic 1 = divide-by-4 clock input
6
MCR[6]
IR enable (see Figure 17).
logic 0 = enable the standard modem receive and transmit input/output
interface (normal default condition)
logic 1 = enable infrared IrDA receive and transmit inputs/outputs. While
in this mode, the TX/RX output/inputs are routed to the infrared
encoder/decoder. The data input and output levels will conform to the
IrDA infrared interface requirement. As such, while in this mode, the
infrared TX output will be a logic 0 during idle data conditions.
5
MCR[5]
Reserved; set to ‘0’.
4
MCR[4]
Loop-back. Enable the local loop-back mode (diagnostics). In this mode the
transmitter output (TX) and the receiver input (RX), CTS, DSR, CD, and RI
are disconnected from the SC16C652B I/O pins. Internally the modem data
and control pins are connected into a loop-back data configuration (see
Figure 5). In this mode, the receiver and transmitter interrupts remain fully
operational. The Modem Control Interrupts are also operational, but the
interrupts’ sources are switched to the lower four bits of the Modem Control.
Interrupts continue to be controlled by the IER register.
logic 0 = disable Loop-back mode (normal default condition)
logic 1 = enable local Loop-back mode (diagnostics)
3
MCR[3]
OP2/INT enable
logic 0 = forces INT (A, B) outputs to the 3-state mode and sets OP2 to a
logic 1 (normal default condition)
logic 1 = forces the INT (A, B) outputs to the active mode and sets OP2 to
a logic 0
2
MCR[2]
(OP1). OP1A/OP1B are not available as an external signal in the
SC16C652B. This bit is instead used in the Loop-back mode only. In the
Loop-back mode, this bit is used to write the state of the modem RI interface
signal.
1
MCR[1]
RTS
logic 0 = force RTS output to a logic 1 (normal default condition)
logic 1 = force RTS output to a logic 0
0
MCR[0]
DTR
logic 0 = force DTR output to a logic 1 (normal default condition)
logic 1 = force DTR output to a logic 0
SC16C652B_4
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Rev. 04 — 1 September 2005
22 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
7.7 Line Status Register (LSR)
This register provides the status of data transfers between the SC16C652B and the CPU.
Table 21:
Line Status Register bits description
Bit
Symbol
Description
7
LSR[7]
FIFO data error.
logic 0 = no error (normal default condition)
logic 1 = at least one parity error, framing error or break indication is in the
current FIFO data. This bit is cleared when there are no remaining error flags
associated with the remaining data in the FIFO.
6
LSR[6]
THR and TSR empty. This bit is the Transmit Empty indicator. This bit is set to a
logic 1 whenever the transmit holding register and the transmit shift register are
both empty. It is reset to logic 0 whenever either the THR or TSR contains a data
character. In the FIFO mode, this bit is set to ‘1’ whenever the transmit FIFO and
transmit shift register are both empty.
5
LSR[5]
THR empty. This bit is the Transmit Holding Register Empty indicator. This bit
indicates that the UART is ready to accept a new character for transmission. In
addition, this bit causes the UART to issue an interrupt to CPU when the THR
interrupt enable is set. The THR bit is set to a logic 1 when a character is
transferred from the transmit holding register into the transmitter shift register.
The bit is reset to a logic 0 concurrently with the loading of the transmitter
holding register by the CPU. In the FIFO mode, this bit is set when the transmit
FIFO is empty; it is cleared when at least 1 byte is written to the transmit FIFO.
4
LSR[4]
Break interrupt.
logic 0 = no break condition (normal default condition)
logic 1 = the receiver received a break signal (RX was a logic 0 for one
character frame time). In the FIFO mode, only one break character is loaded
into the FIFO.
3
LSR[3]
Framing error.
logic 0 = no framing error (normal default condition)
logic 1 = framing error. The receive character did not have a valid stop bit(s). In
the FIFO mode, this error is associated with the character at the top of the
FIFO.
2
LSR[2]
Parity error.
logic 0 = no parity error (normal default condition
logic 1 = parity error. The receive character does not have correct parity
information and is suspect. In the FIFO mode, this error is associated with the
character at the top of the FIFO.
1
LSR[1]
Overrun error.
logic 0 = no overrun error (normal default condition)
logic 1 = overrun error. A data overrun error occurred in the Receive Shift
Register. This happens when additional data arrives while the FIFO is full. In
this case, the previous data in the shift register is overwritten. Note that under
this condition, the data byte in the Receive Shift Register is not transferred into
the FIFO, therefore the data in the FIFO is not corrupted by the error.
0
LSR[0]
Receive data ready.
logic 0 = no data in Receive Holding Register or FIFO (normal default
condition)
logic 1 = data has been received and is saved in the Receive Holding Register
or FIFO
SC16C652B_4
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Rev. 04 — 1 September 2005
23 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
7.8 Modem Status Register (MSR)
This register provides the current state of the control interface signals from the modem, or
other peripheral device to which the SC16C652B is connected. Four bits of this register
are used to indicate the changed information. These bits are set to a logic 1 whenever a
control input from the modem changes state. These bits are set to a logic 0 whenever the
CPU reads this register.
Table 22:
Modem Status Register bits description
Bit
Symbol
Description
7
MSR[7]
CD. During normal operation, this bit is the complement of the CD input.
Reading this bit in the loop-back mode produces the state of MCR[3] (OP2).
6
MSR[6]
RI. During normal operation, this bit is the complement of the RI input.
Reading this bit in the loop-back mode produces the state of MCR[2] (OP1).
5
MSR[5]
DSR. During normal operation, this bit is the complement of the DSR input.
During the loop-back mode, this bit is equivalent to MCR[0] (DTR).
4
MSR[4]
CTS. During normal operation, this bit is the complement of the CTS input.
During the loop-back mode, this bit is equivalent to MCR[1] (RTS).
3
MSR[3]
∆CD
[1]
logic 0 = no CD change (normal default condition)
logic 1 = the CD input to the SC16C652B has changed state since the
last time it was read. A modem Status Interrupt will be generated.
2
MSR[2]
∆RI
[1]
logic 0 = no RI change (normal default condition)
logic 1 = the RI input to the SC16C652B has changed from a logic 0 to a
logic 1. A modem Status Interrupt will be generated.
1
MSR[1]
∆DSR
[1]
logic 0 = no DSR change (normal default condition)
logic 1 = the DSR input to the SC16C652B has changed state since the
last time it was read. A modem Status Interrupt will be generated.
0
MSR[0]
∆CTS
[1]
logic 0 = no CTS change (normal default condition)
logic 1 = the CTS input to the SC16C652B has changed state since the
last time it was read. A modem Status Interrupt will be generated.
[1]
Whenever any MSR bit 3:0 is set to logic 1, a Modem Status Interrupt will be generated.
7.9 Scratchpad Register (SPR)
The SC16C652B provides a temporary data register to store 8 bits of user information.
SC16C652B_4
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SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
7.10 Enhanced Feature Register (EFR)
Enhanced features are enabled or disabled using this register.
Bits 0 through 4 provide single or dual character software flow control selection. When the
Xon1 and Xon2 and/or Xoff1 and Xoff2 modes are selected, the double 8-bit words are
concatenated into two sequential numbers.
Table 23:
Enhanced Feature Register bits description
Bit
Symbol
Description
7
EFR[7]
Automatic CTS flow control.
logic 0 = automatic CTS flow control is disabled (normal default condition)
logic 1 = enable automatic CTS flow control. Transmission will stop when
CTS goes to a logical 1. Transmission will resume when the CTS pin returns
to a logical 0.
6
EFR[6]
Automatic RTS flow control. Automatic RTS may be used for hardware flow
control by enabling EFR[6]. When Auto-RTS is selected, an interrupt will be
generated when the receive FIFO is filled to the programmed trigger level and
RTS will go to a logic 1 at the next trigger level. RTS will return to a logic 0 when
data is unloaded below the next lower trigger level (programmed trigger level 1).
The state of this register bit changes with the status of the hardware flow
control. RTS functions normally when hardware flow control is disabled.
logic
0 = automatic RTS flow control is disabled (normal default condition)
logic 1 = enable automatic RTS flow control
5
EFR[5]
Special Character Detect.
logic 0 = special character detect disabled (normal default condition)
logic 1 = special character detect enabled. The SC16C652B compares each
incoming receive character with Xoff2 data. If a match exists, the received
data will be transferred to FIFO and ISR[4] will be set to indicate detection of
special character. Bit-0 in the X-registers corresponds with the LSB bit for the
receive character. When this feature is enabled, the normal software flow
control must be disabled (EFR[3:0] must be set to a logic 0).
4
EFR[4]
Enhanced function control bit. The content of IER[7:4], ISR[5:4], FCR[5:4], and
MCR[7:5] can be modified and latched. After modifying any bits in the enhanced
registers, EFR[4] can be set to a logic 0 to latch the new values. This feature
prevents existing software from altering or overwriting the SC16C652B
enhanced functions.
logic 0 = disable/latch enhanced features. IER[7:4], ISR[5:4], FCR[5:4], and
MCR[7:5] are saved to retain the user settings, then IER[7:4] ISR[5:4],
FCR[5:4], and MCR[7:5] are set to a logic 0 to be compatible with SC16C554
mode. (Normal default condition.)
logic 1 = enables the enhanced functions. When this bit is set to a logic 1, all
enhanced features of the SC16C652B are enabled and user settings stored
during a reset will be restored.
3:0
EFR[3:0] Cont-3:0 Tx, Rx control. Logic 0 or cleared is the default condition.
Combinations of software flow control can be selected by programming these
bits. See Table 24.
SC16C652B_4
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Rev. 04 — 1 September 2005
25 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
Software flow control functions [1]
Table 24:
Cont-3
Cont-2
Cont-1
Cont-0
TX, RX software flow controls
0
0
X
X
No transmit flow control
1
0
X
X
Transmit Xon1/Xoff1
0
1
X
X
Transmit Xon2/Xoff2
1
1
X
X
Transmit Xon1 and Xon2/Xoff1 and Xoff2
X
X
0
0
No receive flow control
X
X
1
0
Receiver compares Xon1/Xoff1
X
X
0
1
Receiver compares Xon2/Xoff2
1
0
1
1
Transmit Xon1/Xoff1
Receiver compares Xon1 and Xon2, Xoff1 and Xoff2
0
1
1
1
Transmit Xon2/Xoff2
Receiver compares Xon1 and Xon2/Xoff1 and Xoff2
1
1
1
1
Transmit Xon1 and Xon2/Xoff1 and Xoff2
Receiver compares Xon1 and Xon2/Xoff1 and Xoff2
[1]
When using a software flow control the Xon/Xoff characters cannot be used for data transfer.
7.11 SC16C652B external reset condition
Table 25:
Reset state for registers
Register
Reset state
IER
IER[7:0] = 0
FCR
FCR[7:0] = 0
ISR
ISR[7:1] = 0; ISR[0] = 1
LCR
LCR[7:0] = 0
MCR
MCR[7:0] = 0
LSR
LSR[7] = 0; LSR[6:5] = 1; LSR[4:0] = 0
MSR
MSR[7:4] = input signals; MSR[3:0] = 0
SPR
SFR[7:0] = 1
DLL
DLL[7:0] = X
DLM
DLM[7:0] = X
Table 26:
Reset state for outputs
Output
Reset state
TXA, TXB
logic 1
OP2A, OP2B
logic 1
RTSA, RTSB
logic 1
DTRA, DTRB
logic 1
INTA, INTB
3-state condition
SC16C652B_4
Product data sheet
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Rev. 04 — 1 September 2005
26 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
8. Limiting values
Table 27: Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol
Parameter
VCC
supply voltage
Conditions
Min
Max
Unit
-
7
V
GND − 0.3
VCC + 0.3
V
−40
+85
°C
Vn
voltage at any pin
Tamb
ambient temperature
Tstg
storage temperature
−65
+150
°C
Ptot(pack)
total power dissipation per package
-
500
mW
operating in free air
9. Static characteristics
Table 28: Static characteristics
Tamb = −40 °C to +85 °C; tolerance of VCC = ± 10 %; unless otherwise specified.
Symbol
Parameter
Conditions
VCC = 2.5 V
VCC = 3.3 V
VCC = 5.0 V
Min
Min
Min
Max
Max
Unit
Max
VIL(CK)
LOW-level clock input voltage
−0.3
0.45
−0.3
0.6
−0.5
0.6
V
VIH(CK)
HIGH-level clock input voltage
1.8
VCC
2.4
VCC
3.0
VCC
V
VIL
LOW-level input voltage
(except X1 clock)
−0.3
0.65
−0.3
0.8
−0.5
0.8
V
VIH
HIGH-level input voltage
(except X1 clock)
1.6
-
2.0
-
2.2
-
V
VOL
LOW-level output voltage on all
outputs [1]
IOL = 5 mA
(databus)
-
-
-
-
-
0.4
V
IOL = 4 mA
(other outputs)
-
-
-
0.4
-
-
V
IOL = 2 mA
(databus)
-
0.4
-
-
-
-
V
IOL = 1.6 mA
(other outputs)
-
0.4
-
-
-
-
V
IOH = −5 mA
(databus)
-
-
-
-
2.4
-
V
IOH = −1 mA
(other outputs)
-
-
2.0
-
-
-
V
IOH = −800 µA
(data bus)
1.85
-
-
-
-
-
V
IOH = −400 µA
(other outputs)
1.85
-
-
-
-
-
V
VOH
HIGH-level output voltage
ILIL
LOW-level input leakage current
-
±10
-
±10
-
±10
µA
ICL
clock leakage current
-
±30
-
±30
-
±30
µA
ICC
supply current
-
3.5
-
4.5
-
4.5
mA
-
50
-
50
-
50
µA
-
5
-
5
-
5
pF
ICCsleep
sleep current
Ci
input capacitance
f = 5 MHz
[2]
[1]
Except XTAL2, VOL = 1 V typical.
[2]
Sleep current might be higher if there is any activity on the UART data bus during Sleep mode.
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SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
10. Dynamic characteristics
Table 29: Dynamic characteristics
Tamb = −40 °C to +85 °C; tolerance of VCC = ± 10 %; unless otherwise specified.
Symbol
Parameter
Conditions
VCC = 2.5 V
Min
t1w, t2w
clock pulse duration
fXTAL
oscillator/clock frequency
t6s
VCC = 3.3 V
Max
Min
Max
10
-
6
-
-
48
-
80
address set-up time
0
-
0
-
t6h
address hold time
0
-
0
-
t7d
IOR delay from chip select
t7w
IOR strobe width
t7h
chip select hold time from
IOR
[1] [2]
25 pF load
VCC = 5.0 V
Min
6
Unit
Max
-
ns
80
MHz
0
-
ns
0
-
ns
10
-
10
-
10
-
ns
77
-
26
-
23
-
ns
0
-
0
-
0
-
ns
t9d
read cycle delay
25 pF load
20
-
20
-
20
-
ns
t12d
delay from IOR to data
25 pF load
-
77
-
26
-
23
ns
t12h
data disable time
25 pF load
-
15
-
15
-
15
ns
t13d
IOW delay from chip select
10
-
10
-
10
-
ns
t13w
IOW strobe width
20
-
20
-
15
-
ns
t13h
chip select hold time from
IOW
0
-
0
-
0
-
ns
t15d
write cycle delay
25
-
25
-
20
-
ns
t16s
data set-up time
20
-
20
-
15
-
ns
t16h
data hold time
15
-
5
-
5
-
ns
t17d
delay from IOW to output
25 pF load
-
100
-
33
-
29
ns
t18d
delay to set interrupt from
Modem input
25 pF load
-
100
-
24
-
23
ns
t19d
delay to reset interrupt from 25 pF load
IOR
-
100
-
24
-
23
ns
t20d
delay from stop to set
interrupt
-
1TRCLK
-
1TRCLK
-
1TRCLK
s
t21d
delay from IOR to reset
interrupt
-
100
-
29
-
28
ns
t22d
delay from start to set
interrupt
-
100
-
45
-
40
ns
t23d
delay from IOW to transmit
start
t24d
delay from IOW to reset
interrupt
t25d
delay from stop to set
RXRDY
t26d
t27d
[3]
25 pF load
[3]
8TRCLK 24TRCLK 8TRCLK 24TRCLK 8TRCLK 24TRCLK s
-
100
-
45
-
40
ns
-
1TRCLK
-
1TRCLK
-
1TRCLK
s
delay from IOR to reset
RXRDY
-
100
-
45
-
40
ns
delay from IOW to set
TXRDY
-
100
-
45
-
40
ns
[3]
SC16C652B_4
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Rev. 04 — 1 September 2005
28 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
Table 29: Dynamic characteristics
Tamb = −40 °C to +85 °C; tolerance of VCC = ± 10 %; unless otherwise specified.
Symbol
Parameter
Conditions
VCC = 2.5 V
Min
t28d
delay from start to reset
TXRDY
tRESET
RESET pulse width
N
[3]
baud rate divisor
VCC = 3.3 V
Max
Min
VCC = 5.0 V
Max
Min
Unit
Max
-
8TRCLK
-
8TRCLK
-
8TRCLK
s
200
-
40
-
40
-
ns
1
(216
− 1) 1
(216
− 1) 1
[1]
Applies to external clock, crystal oscillator max 24 MHz.
[2]
Maximum frequency = -------
[3]
RCLK is an internal signal derived from divisor latch LSB (DLL) and divisor latch MSB (DLM) divisor latches.
(216
− 1)
1
t 3w
10.1 Timing diagrams
t6h
valid
address
A0 to A2
t13h
t6s
active
CSx
t13d
IOW
t15d
t13w
active
t16s
D0 to D7
t16h
data
002aaa109
Fig 6. General write timing
SC16C652B_4
Product data sheet
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Rev. 04 — 1 September 2005
29 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
t6h
valid
address
A0 to A2
t7h
t6s
active
CSx
t7d
IOR
t9d
t7w
active
t12h
t12d
D0 to D7
data
002aaa110
Fig 7. General read timing
IOW
active
t17d
RTS
DTR
change of state
change of state
CD
CTS
DSR
change of state
change of state
t18d
INT
t18d
active
active
active
t19d
IOR
active
active
active
t18d
change of state
RI
002aaa352
Fig 8. Modem input/output timing
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30 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
t2w
t1w
EXTERNAL
CLOCK
002aaa112
t3w
1
f XTAL = ------t 3w
Fig 9. External clock timing
start
bit
RX
parity
bit
data bits (0 to 7)
D0
D1
D2
D3
D4
D5
D6
stop
bit
next
data
start
bit
D7
5 data bits
6 data bits
7 data bits
t20d
active
INT
t21d
active
IOR
16 baud rate clock
002aaa113
Fig 10. Receive timing
SC16C652B_4
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31 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
start
bit
D0
RX
parity
bit
data bits (0 to 7)
D1
D2
D3
D4
D5
D6
stop
bit
next
data
start
bit
D7
t25d
active data
ready
RXRDY
t26d
active
IOR
002aab063
Fig 11. Receive ready timing in non-FIFO mode
start
bit
RX
parity
bit
data bits (0 to 7)
D0
D1
D2
D3
D4
D5
D6
stop
bit
D7
first byte that
reaches the
trigger level
t25d
active data
ready
RXRDY
t26d
active
IOR
002aab064
Fig 12. Receive ready timing in FIFO mode
SC16C652B_4
Product data sheet
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Rev. 04 — 1 September 2005
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SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
start
bit
parity
bit
data bits (0 to 7)
TX
D0
D1
D2
D3
D4
D5
D6
stop
bit
next
data
start
bit
D7
5 data bits
6 data bits
7 data bits
active
transmitter ready
INT
t22d
t24d
t23d
IOW
active
active
16 baud rate clock
002aaa116
Fig 13. Transmit timing
start
bit
D0
TX
IOW
parity
bit
data bits (0 to 7)
D1
D2
D3
D4
D5
D6
stop
bit
next
data
start
bit
D7
active
t28d
D0 to D7
byte #1
t27d
TXRDY
active transmitter
ready
transmitter
not ready
002aab062
Fig 14. Transmit ready timing in non-FIFO mode
SC16C652B_4
Product data sheet
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Rev. 04 — 1 September 2005
33 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
start
bit
data bits (0 to 7)
D0
TX
parity
bit
D1
D2
D3
D4
D5
D6
stop
bit
D7
5 data bits
6 data bits
7 data bits
IOW
active
t28d
D0 to D7
byte #32
t27d
TXRDY
FIFO full
002aab065
Fig 15. Transmit ready timing in FIFO mode (DMA mode ‘1’)
SC16C652B_4
Product data sheet
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Rev. 04 — 1 September 2005
34 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
UART frame
start
data bits
0
TX data
1
0
1
0
stop
0
1
1
0
1
IrDA TX data
1/ bit time
2
bit
time
3/ bit time
16
002aaa212
Fig 16. Infrared transmit timing
IrDA RX data
bit
time
RX data
0 to 1 16× clock delay
0
1
0
1
start
0
0
data bits
1
1
0
1
stop
UART frame
002aaa213
Fig 17. Infrared receive timing
SC16C652B_4
Product data sheet
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Rev. 04 — 1 September 2005
35 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
11. Package outline
LQFP48: plastic low profile quad flat package; 48 leads; body 7 x 7 x 1.4 mm
SOT313-2
c
y
X
36
25
A
37
24
ZE
e
E HE
A A2
(A 3)
A1
w M
θ
bp
pin 1 index
Lp
L
13
48
1
detail X
12
ZD
e
v M A
w M
bp
D
B
HD
v M B
0
2.5
5 mm
scale
DIMENSIONS (mm are the original dimensions)
UNIT
A
max.
A1
A2
A3
bp
c
D (1)
E (1)
e
HD
HE
L
Lp
v
w
y
mm
1.6
0.20
0.05
1.45
1.35
0.25
0.27
0.17
0.18
0.12
7.1
6.9
7.1
6.9
0.5
9.15
8.85
9.15
8.85
1
0.75
0.45
0.2
0.12
0.1
Z D (1) Z E (1)
θ
0.95
0.55
7
o
0
0.95
0.55
o
Note
1. Plastic or metal protrusions of 0.25 mm maximum per side are not included.
REFERENCES
OUTLINE
VERSION
IEC
JEDEC
SOT313-2
136E05
MS-026
JEITA
EUROPEAN
PROJECTION
ISSUE DATE
00-01-19
03-02-25
Fig 18. Package outline SOT313-2 (LQFP48)
SC16C652B_4
Product data sheet
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Rev. 04 — 1 September 2005
36 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
HVQFN32: plastic thermal enhanced very thin quad flat package; no leads;
32 terminals; body 5 x 5 x 0.85 mm
A
B
D
SOT617-1
terminal 1
index area
A
A1
E
c
detail X
C
e1
e
1/2 e
16
y
y1 C
v M C A B
w M C
b
9
L
17
8
e
e2
Eh
1/2 e
1
terminal 1
index area
24
32
25
X
Dh
0
2.5
5 mm
scale
DIMENSIONS (mm are the original dimensions)
UNIT
A(1)
max.
A1
b
c
D (1)
Dh
E (1)
Eh
e
e1
e2
L
v
w
y
y1
mm
1
0.05
0.00
0.30
0.18
0.2
5.1
4.9
3.25
2.95
5.1
4.9
3.25
2.95
0.5
3.5
3.5
0.5
0.3
0.1
0.05
0.05
0.1
Note
1. Plastic or metal protrusions of 0.075 mm maximum per side are not included.
REFERENCES
OUTLINE
VERSION
IEC
JEDEC
JEITA
SOT617-1
---
MO-220
---
EUROPEAN
PROJECTION
ISSUE DATE
01-08-08
02-10-18
Fig 19. Package outline SOT617-1 (HVQFN32)
SC16C652B_4
Product data sheet
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Rev. 04 — 1 September 2005
37 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
12. Soldering
12.1 Introduction to soldering surface mount packages
This text gives a very brief insight to a complex technology. A more in-depth account of
soldering ICs can be found in our Data Handbook IC26; Integrated Circuit Packages
(document order number 9398 652 90011).
There is no soldering method that is ideal for all surface mount IC packages. Wave
soldering can still be used for certain surface mount ICs, but it is not suitable for fine pitch
SMDs. In these situations reflow soldering is recommended.
12.2 Reflow soldering
Reflow soldering requires solder paste (a suspension of fine solder particles, flux and
binding agent) to be applied to the printed-circuit board by screen printing, stencilling or
pressure-syringe dispensing before package placement. Driven by legislation and
environmental forces the worldwide use of lead-free solder pastes is increasing.
Several methods exist for reflowing; for example, convection or convection/infrared
heating in a conveyor type oven. Throughput times (preheating, soldering and cooling)
vary between 100 seconds and 200 seconds depending on heating method.
Typical reflow peak temperatures range from 215 °C to 270 °C depending on solder paste
material. The top-surface temperature of the packages should preferably be kept:
• below 225 °C (SnPb process) or below 245 °C (Pb-free process)
– for all BGA, HTSSON..T and SSOP..T packages
– for packages with a thickness ≥ 2.5 mm
– for packages with a thickness < 2.5 mm and a volume ≥ 350 mm3 so called
thick/large packages.
• below 240 °C (SnPb process) or below 260 °C (Pb-free process) for packages with a
thickness < 2.5 mm and a volume < 350 mm3 so called small/thin packages.
Moisture sensitivity precautions, as indicated on packing, must be respected at all times.
12.3 Wave soldering
Conventional single wave soldering is not recommended for surface mount devices
(SMDs) or printed-circuit boards with a high component density, as solder bridging and
non-wetting can present major problems.
To overcome these problems the double-wave soldering method was specifically
developed.
If wave soldering is used the following conditions must be observed for optimal results:
• Use a double-wave soldering method comprising a turbulent wave with high upward
pressure followed by a smooth laminar wave.
• For packages with leads on two sides and a pitch (e):
– larger than or equal to 1.27 mm, the footprint longitudinal axis is preferred to be
parallel to the transport direction of the printed-circuit board;
SC16C652B_4
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SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
– smaller than 1.27 mm, the footprint longitudinal axis must be parallel to the
transport direction of the printed-circuit board.
The footprint must incorporate solder thieves at the downstream end.
• For packages with leads on four sides, the footprint must be placed at a 45° angle to
the transport direction of the printed-circuit board. The footprint must incorporate
solder thieves downstream and at the side corners.
During placement and before soldering, the package must be fixed with a droplet of
adhesive. The adhesive can be applied by screen printing, pin transfer or syringe
dispensing. The package can be soldered after the adhesive is cured.
Typical dwell time of the leads in the wave ranges from 3 seconds to 4 seconds at 250 °C
or 265 °C, depending on solder material applied, SnPb or Pb-free respectively.
A mildly-activated flux will eliminate the need for removal of corrosive residues in most
applications.
12.4 Manual soldering
Fix the component by first soldering two diagonally-opposite end leads. Use a low voltage
(24 V or less) soldering iron applied to the flat part of the lead. Contact time must be
limited to 10 seconds at up to 300 °C.
When using a dedicated tool, all other leads can be soldered in one operation within
2 seconds to 5 seconds between 270 °C and 320 °C.
12.5 Package related soldering information
Table 30:
Suitability of surface mount IC packages for wave and reflow soldering methods
Package [1]
Soldering method
Wave
Reflow [2]
BGA, HTSSON..T [3], LBGA, LFBGA, SQFP,
SSOP..T [3], TFBGA, VFBGA, XSON
not suitable
suitable
DHVQFN, HBCC, HBGA, HLQFP, HSO, HSOP,
HSQFP, HSSON, HTQFP, HTSSOP, HVQFN,
HVSON, SMS
not suitable [4]
suitable
PLCC [5], SO, SOJ
suitable
suitable
not
recommended [5] [6]
suitable
SSOP, TSSOP, VSO, VSSOP
not
recommended [7]
suitable
CWQCCN..L [8], PMFP [9], WQCCN..L [8]
not suitable
LQFP, QFP, TQFP
[1]
For more detailed information on the BGA packages refer to the (LF)BGA Application Note (AN01026);
order a copy from your Philips Semiconductors sales office.
[2]
All surface mount (SMD) packages are moisture sensitive. Depending upon the moisture content, the
maximum temperature (with respect to time) and body size of the package, there is a risk that internal or
external package cracks may occur due to vaporization of the moisture in them (the so called popcorn
effect). For details, refer to the Drypack information in the Data Handbook IC26; Integrated Circuit
Packages; Section: Packing Methods.
[3]
These transparent plastic packages are extremely sensitive to reflow soldering conditions and must on no
account be processed through more than one soldering cycle or subjected to infrared reflow soldering with
peak temperature exceeding 217 °C ± 10 °C measured in the atmosphere of the reflow oven. The package
body peak temperature must be kept as low as possible.
SC16C652B_4
Product data sheet
not suitable
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Rev. 04 — 1 September 2005
39 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
[4]
These packages are not suitable for wave soldering. On versions with the heatsink on the bottom side, the
solder cannot penetrate between the printed-circuit board and the heatsink. On versions with the heatsink
on the top side, the solder might be deposited on the heatsink surface.
[5]
If wave soldering is considered, then the package must be placed at a 45° angle to the solder wave
direction. The package footprint must incorporate solder thieves downstream and at the side corners.
[6]
Wave soldering is suitable for LQFP, QFP and TQFP packages with a pitch (e) larger than 0.8 mm; it is
definitely not suitable for packages with a pitch (e) equal to or smaller than 0.65 mm.
[7]
Wave soldering is suitable for SSOP, TSSOP, VSO and VSSOP packages with a pitch (e) equal to or larger
than 0.65 mm; it is definitely not suitable for packages with a pitch (e) equal to or smaller than 0.5 mm.
[8]
Image sensor packages in principle should not be soldered. They are mounted in sockets or delivered
pre-mounted on flex foil. However, the image sensor package can be mounted by the client on a flex foil by
using a hot bar soldering process. The appropriate soldering profile can be provided on request.
[9]
Hot bar soldering or manual soldering is suitable for PMFP packages.
13. Abbreviations
Table 31:
Abbreviations
Acronym
Description
FIFO
First In, First Out
UART
Universal Asynchronous Receiver/Transmitter
CPU
Central Processing Unit
ISDN
Integrated Service Digital Network
DMA
Direct Memory Access
SC16C652B_4
Product data sheet
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Rev. 04 — 1 September 2005
40 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
14. Revision history
Table 32:
Revision history
Document ID
Release date
Data sheet status
Change notice
Doc. number
Supersedes
SC16C652B_4
20050901
Product data sheet
-
-
SC16C652B-03
Modifications:
•
The format of this data sheet has be redesigned to comply with the new presentation and
information standard of Philips Semiconductors.
•
•
Table 4 “Internal registers decoding” on page 8, Table note 3: changed “BF(HEX)” to “BFh”
Section 6.8 “Programmable baud rate generator” on page 11, 3rd paragraph: changed from
“... from 1 to 216 − 1.” to “... from 1 to (216 − 1).”
•
•
•
Table 6 on page 12: added “(bit/s)” to first column heading
•
•
•
Table 18 “LCR[2] stop bit length” on page 21: added “(bits)” to column heading “Word length”
Add new Section 6.11 “Sleep mode” on page 14
Table 9 “SC16C652B internal registers” on page 15: removed shading, added (new) Table note 2
and references to it in previously shaded table cells
Table 19 “LCR[1:0] word length” on page 21: added “(bits)” to column heading “Word length”
Table 28 “Static characteristics” on page 27:
– added row ICCsleep and new Table note 2
– Table note 1: changed “x2” to “XTAL2”
•
Table 29 “Dynamic characteristics” on page 28:
– changed symbol “t3w” to “fXTAL” and added (new) Table note 2
– presentation of values for t20d, t23d, t25d, t28d changed: “TRCLK” appended to multiplier; Unit
changed from “Rclk” to “s”; Table note 3 added and referenced at these 4 timing
measurements
– Unit “Rclk” deleted from row for symbol “N” (N is a number)
•
•
•
•
SC16C652B-03
Modifications:
added equation to Figure 9 “External clock timing” on page 31
signal TXRDY modified in Figure 14 “Transmit ready timing in non-FIFO mode” on page 33
Figure 15 “Transmit ready timing in FIFO mode (DMA mode ‘1’)” on page 34: changed
“BYTE #1” to “byte #32”
added Section 13 “Abbreviations”
20041210
•
Product data
-
9397 750 14452
SC16C652B-02
There is no modification to the data sheet. However, reader is advised to refer to
AN10333 (Rev. 01) “SC16CXXXB baud rate deviation tolerance” (9397 750 14411) that was
released together with this revision.
SC16C652B-02
20040617
Product data
-
9397 750 13123
SC16C652B-01
SC16C652B-01
20040326
Product data
-
9397 750 11972
-
SC16C652B_4
Product data sheet
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Rev. 04 — 1 September 2005
41 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
15. Data sheet status
Level
Data sheet status [1]
Product status [2] [3]
Definition
I
Objective data
Development
This data sheet contains data from the objective specification for product development. Philips
Semiconductors reserves the right to change the specification in any manner without notice.
II
Preliminary data
Qualification
This data sheet contains data from the preliminary specification. Supplementary data will be published
at a later date. Philips Semiconductors reserves the right to change the specification without notice, in
order to improve the design and supply the best possible product.
III
Product data
Production
This data sheet contains data from the product specification. Philips Semiconductors reserves the
right to make changes at any time in order to improve the design, manufacturing and supply. Relevant
changes will be communicated via a Customer Product/Process Change Notification (CPCN).
[1]
Please consult the most recently issued data sheet before initiating or completing a design.
[2]
The product status of the device(s) described in this data sheet may have changed since this data sheet was published. The latest information is available on the Internet at
URL http://www.semiconductors.philips.com.
[3]
For data sheets describing multiple type numbers, the highest-level product status determines the data sheet status.
16. Definitions
customers using or selling these products for use in such applications do so
at their own risk and agree to fully indemnify Philips Semiconductors for any
damages resulting from such application.
Short-form specification — The data in a short-form specification is
extracted from a full data sheet with the same type number and title. For
detailed information see the relevant data sheet or data handbook.
Right to make changes — Philips Semiconductors reserves the right to
make changes in the products - including circuits, standard cells, and/or
software - described or contained herein in order to improve design and/or
performance. When the product is in full production (status ‘Production’),
relevant changes will be communicated via a Customer Product/Process
Change Notification (CPCN). Philips Semiconductors assumes no
responsibility or liability for the use of any of these products, conveys no
license or title under any patent, copyright, or mask work right to these
products, and makes no representations or warranties that these products are
free from patent, copyright, or mask work right infringement, unless otherwise
specified.
Limiting values definition — Limiting values given are in accordance with
the Absolute Maximum Rating System (IEC 60134). Stress above one or
more of the limiting values may cause permanent damage to the device.
These are stress ratings only and operation of the device at these or at any
other conditions above those given in the Characteristics sections of the
specification is not implied. Exposure to limiting values for extended periods
may affect device reliability.
Application information — Applications that are described herein for any
of these products are for illustrative purposes only. Philips Semiconductors
make no representation or warranty that such applications will be suitable for
the specified use without further testing or modification.
18. Trademarks
17. Disclaimers
Notice — All referenced brands, product names, service names and
trademarks are the property of their respective owners.
Life support — These products are not designed for use in life support
appliances, devices, or systems where malfunction of these products can
reasonably be expected to result in personal injury. Philips Semiconductors
19. Contact information
For additional information, please visit: http://www.semiconductors.philips.com
For sales office addresses, send an email to: [email protected]
SC16C652B_4
Product data sheet
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Rev. 04 — 1 September 2005
42 of 43
SC16C652B
Philips Semiconductors
Dual UART with 32-byte FIFOs and IrDA encoder/decoder
20. Contents
1
2
3
4
5
5.1
5.2
6
6.1
6.2
6.3
6.4
6.5
6.6
6.7
6.8
6.9
6.10
6.11
7
7.1
General description . . . . . . . . . . . . . . . . . . . . . . 1
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Ordering information . . . . . . . . . . . . . . . . . . . . . 2
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Pinning information . . . . . . . . . . . . . . . . . . . . . . 4
Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 5
Functional description . . . . . . . . . . . . . . . . . . . 7
UART A-B functions . . . . . . . . . . . . . . . . . . . . . 8
Internal registers. . . . . . . . . . . . . . . . . . . . . . . . 8
FIFO operation . . . . . . . . . . . . . . . . . . . . . . . . . 9
Hardware flow control . . . . . . . . . . . . . . . . . . . . 9
Software flow control . . . . . . . . . . . . . . . . . . . . 9
Special feature software flow control . . . . . . . 10
Hardware/software and time-out interrupts. . . 10
Programmable baud rate generator . . . . . . . . 11
DMA operation . . . . . . . . . . . . . . . . . . . . . . . . 12
Loop-back mode . . . . . . . . . . . . . . . . . . . . . . . 12
Sleep mode. . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Register descriptions . . . . . . . . . . . . . . . . . . . 15
Transmit (THR) and Receive (RHR) Holding
Registers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.2
Interrupt Enable Register (IER) . . . . . . . . . . . 16
7.2.1
IER versus Transmit/Receive FIFO interrupt
mode operation. . . . . . . . . . . . . . . . . . . . . . . . 17
7.2.2
IER versus Receive/Transmit FIFO polled
mode operation. . . . . . . . . . . . . . . . . . . . . . . . 17
7.3
FIFO Control Register (FCR) . . . . . . . . . . . . . 18
7.3.1
DMA mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7.3.1.1
Mode 0 (FCR bit 3 = 0) . . . . . . . . . . . . . . . . . . 18
7.3.1.2
Mode 1 (FCR bit 3 = 1) . . . . . . . . . . . . . . . . . . 18
7.3.2
FIFO mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
7.4
Interrupt Status Register (ISR) . . . . . . . . . . . . 20
7.5
Line Control Register (LCR) . . . . . . . . . . . . . . 21
7.6
Modem Control Register (MCR) . . . . . . . . . . . 22
7.7
Line Status Register (LSR) . . . . . . . . . . . . . . . 23
7.8
Modem Status Register (MSR). . . . . . . . . . . . 24
7.9
Scratchpad Register (SPR) . . . . . . . . . . . . . . 24
7.10
Enhanced Feature Register (EFR) . . . . . . . . . 25
7.11
SC16C652B external reset condition . . . . . . . 26
8
Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 27
9
Static characteristics. . . . . . . . . . . . . . . . . . . . 27
10
Dynamic characteristics . . . . . . . . . . . . . . . . . 28
10.1
Timing diagrams . . . . . . . . . . . . . . . . . . . . . . . 29
11
Package outline . . . . . . . . . . . . . . . . . . . . . . . . 36
12
Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
12.1
12.2
12.3
12.4
12.5
13
14
15
16
17
18
19
Introduction to soldering surface mount
packages . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reflow soldering. . . . . . . . . . . . . . . . . . . . . . .
Wave soldering. . . . . . . . . . . . . . . . . . . . . . . .
Manual soldering . . . . . . . . . . . . . . . . . . . . . .
Package related soldering information . . . . . .
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . .
Revision history . . . . . . . . . . . . . . . . . . . . . . .
Data sheet status. . . . . . . . . . . . . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . .
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contact information . . . . . . . . . . . . . . . . . . . .
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© Koninklijke Philips Electronics N.V. 2005
All rights are reserved. Reproduction in whole or in part is prohibited without the prior
written consent of the copyright owner. The information presented in this document does
not form part of any quotation or contract, is believed to be accurate and reliable and may
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consequence of its use. Publication thereof does not convey nor imply any license under
patent- or other industrial or intellectual property rights.
Date of release: 1 September 2005
Document number: SC16C652B_4
Published in The Netherlands