SB16C1054PCI_Data Sheet_EN

ManualsBrandsSystemBase ManualsElectronic ComponentsPCI to Quad UART with 256 Byte FIFO Bridge Controller - 60pcs Bundle

SB16C1054PCI

PCI Target Interface Controller

with Quad-UART

JULY 2013 REV 1.04

13.12 Transmit FIFO Count Register (TCR, Page 2)

TCR shows the number of characters that can be stored in TX FIFO. In 64-byte FIFO

mode, it consists of only TCR[6:0]. If the number of characters that can be stored in TX

FIFO is 0, it is shown as 0000_0000b and if 64, it is shown as 0100_0000b. In 256-byte

FIFO mode, it consists of ISR[7] + TCR[7:0]. If the number of characters that can be

stored in TX FIFO is 0, it is shown as 0_0000_0000b and if 255, it is shown as

0_1111_1111b. And in case of the maximum number 256, it is shown as 1_0000_0000b.

13.13 Receive FIFO Count Register (RCR, Page 2)

RCR shows the number of characters that is stored in RX FIFO. In 64-byte FIFO mode,

it consists of only RCR[6:0]. If the number of characters that is stored in RX FiFO is 0, it

is shown as 0000_0000b and if 64, it is shown as 0100_0000b. In 256-byte FIFO mode,

it consists of ISR[6] + RCR[7:0]. If the number of characters that is stored in RX FiFO is

0, it is shown as 0_0000_0000b and if 255, it is shown as 0_1111_1111b. And in case of

the maximum number 256, it is shown as 1_0000_0000b.

13.14 Flow Control Status Register (FSR, Page 2)

FSR show the status of operation of TX Hardware Flow Control, RX Hardware Flow

Control, TX Software Flow Control, and RX Software Flow Control.

Table 13–10: Flow Control Status Register Description

Bit

Symbol

Description

7:6

FSR[7:6]

Not used, always 00b.

FSR[5]

TX Hardware Flow Control Status:

0b: When FIFO or Auto-RTS flow control is disabled.

If FIFO and Auto-RTS flow control is enabled, it means the

number of data received in RX FIFO at the first time is less

than the value of FUR, or it means the number of data in RX

FIFO was more than the value of FUR and after the CPU

read them, the number of data that remains unread is less

than or equal to the value of FLR. That is, UART reports

external device that it can receive more characters.

1b: It shows that the number of data received in RX FIFO

exceeds the value of FUR and UART reports external

device that it cannot receive more data. If RX FIFO has

space to store more data, new data are stored in RX FIFO

but after it gets full, they are lost.

For more details, refer to ‘12.2 Hardware Flow Control’.

FSR[4]

TX Software Flow Control Status:

0b: When FIFO or Software flow control is disabled.

If FIFO and Software flow control is enabled, it means