参数资料
型号: ST16C2552CJ44
厂商: EXAR CORP
元件分类: Serial IO/Communication Controller
英文描述: 2 CHANNEL(S), 4M bps, SERIAL COMM CONTROLLER, PQCC44
封装: PLASTIC, LCC-44
文件页数: 2/38页
文件大小: 447K
代理商: ST16C2552CJ44
ST16C2552
8
2.97V TO 5.5V DUAL UART WITH 16-BYTE FIFO
REV. 4.2.1
2.4
Channel A and B Internal Registers
Each UART channel in the 2552 has a set of enhanced registers for controlling, monitoring and data loading
and unloading. The configuration register set is compatible to those already available in the standard single
16C550 and dual ST16C2550. These registers function as data holding registers (THR/RHR), interrupt status
and control registers (ISR/IER), a FIFO control register (FCR), receive line status and control registers (LSR/
LCR), modem status and control registers (MSR/MCR), programmable data rate (clock) divisor registers (DLL/
DLM), and a user accessible scratchpad register (SPR).
Beyond the general 16C2550 features and capabilities, the 2552 offers the Alternate Function Register which
allows simultaneous writes to both channels. All the register functions are discussed in full detail later in
2.5
Simultaneous Write to Channel A and B
During a write mode cycle, the setting of Alternate Function Register (AFR) bit-0 to a logic 1 will override the
CHSEL selection and allows a simultaneous write to both UART channel sections. This functional capability
allow the registers in both UART channels to be modified concurrently, saving individual channel initialization
time. Caution should be exercised, however, when using this capability. Any in-process serial data transfer
may be disrupted by changing an active channel’s mode.
2.6
DMA Mode
The device does not support direct memory access. The DMA Mode (a legacy term) in this document doesn’t
mean “direct memory access” but refers to data block transfer operation. The DMA mode affects the state of
the RXRDY# A/B (MF# A/B becomes RXRDY# A/B output when AFR[2:1] = ‘10’) and TXRDY# A/B output
pins. The transmit and receive FIFO trigger levels provide additional flexibility to the user for block mode
operation. The LSR bits 5-6 provide an indication when the transmitter is empty or has an empty location(s) for
more data. The user can optionally operate the transmit and receive FIFO in the DMA mode (FCR bit-3=1).
When the transmit and receive FIFO are enabled and the DMA mode is disabled (FCR bit-3 = 0), the 2552 is
placed in single-character mode for data transmit or receive operation. When DMA mode is enabled (FCR bit-
3 = 1), the user takes advantage of block mode operation by loading or unloading the FIFO in a block
sequence determined by the programmed trigger level. The following table show their behavior. Also see
Figures 16 through 21.
TABLE 2: TXRDY# AND RXRDY# OUTPUTS IN FIFO AND DMA MODE
PINS
FCR BIT-0=0
(FIFO DISABLED)
FCR BIT-0=1 (FIFO ENABLED)
FCR Bit-3 = 0
(DMA Mode Disabled)
FCR Bit-3 = 1
(DMA Mode Enabled)
RXRDY# A/B
0 = 1 byte.
1 = no data.
0 = at least 1 byte in FIFO
1 = FIFO empty.
1 to 0 transition when FIFO reaches the trigger
level, or timeout occurs.
0 to 1 transition when FIFO empties.
TXRDY# A/B
0 = THR empty.
1 = byte in THR.
0 = FIFO empty.
1 = at least 1 byte in FIFO.
0 = FIFO has at least 1 empty location.
1 = FIFO is full.
相关PDF资料
PDF描述
ST16C552CJ68 2 CHANNEL(S), SERIAL COMM CONTROLLER, PQCC68
ST16C554DCJ68 4 CHANNEL(S), 1.5M bps, SERIAL COMM CONTROLLER, PQCC68
ST1803DHI High Voltage Fast-Switching NPN Power Transistor(高电压快速开关NPN功率晶体管)
ST180S16P1PBF 314 A, 1600 V, SCR, TO-209AB
ST1W008S4A 8 CONTACT(S), MALE, PCMCIA CONNECTOR, SOLDER
相关代理商/技术参数
参数描述
ST16C2552CJ44-F 功能描述:UART 接口集成电路 2.97V-5.5V 16B FIFO temp 0C to 70C; UART RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel
ST16C2552CJ44TR 制造商:Rochester Electronics LLC 功能描述: 制造商:Exar Corporation 功能描述:
ST16C2552CJ44TR-F 功能描述:UART 接口集成电路 DUAL UART W/16BYTE FIFO RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel
ST16C2552CQ48 制造商:未知厂家 制造商全称:未知厂家 功能描述:UART
ST16C2552IJ 制造商:Exar Corporation 功能描述:2 CHANNEL(S), 4M bps, SERIAL COMM CONTROLLER, PQCC44