DataSheet_SB16C1053APCI_v106

SB16C1053APCI

PCI Target Controller with 2 Serial, 1 Parallel and MIO Bus

PCI to 2S+1P with MIO Bus Bridge

JULY 2013 REV 1.06

1b, too.

When IER[6] is set to 1b and RTS# is changed from 0b to 1b by Auto-RTS function,

interrupt occurs and it is displayed on ISR[5:0]. Interrupts by Auto-RTS function are

removed if MSR is read. RTS# is changed from 0b to 1b after the first STOP bit is

received. Figure 11–1 shows the RTS# timing chart while Auto-RTS is enabled.

In Figure 11–1, Data Byte n-1 is received and RTS# is deasserted when the amount of

data in RX FIFO is larger than the value written in FUR. UART completes transmitting

new data (DATA BYTE n) which has started being transmitted even though external

UART recognizes RTS# has been deasserted. After that, the device stops transmitting

more data. If CPU reads data of RX FIFO, the value of RCR decreases and then if that

value equals that of FLR, RTS# is asserted for external UART to transmit new data.

FLR + 1 FLR + 0

RCR[7:0]

START

FUR + 1FUR + 0

RTS#

DATA BYTE n

STOP

RXD

DATA BYTE n

STARTSTOP

DATA BYTE n-1

FUR - 0

FUR - 1

START

FUR -0

IOR#

DATA BYTE 2DATA BYTE 1

Figure 11–1: RTS# Functional Timing

11.2.2 Auto-CTS

Setting EFR[7] to 1b enables Auto-RTS. If enabled, data in TX FIFO are determined to be

transmitted or suspended by the value of CTS#. If 0b, it means external UART can

receive new data and data in TX FIFO are transmitted through TXD pin. If 1b, it means

external UART can not accept more data and data in TX FIFO are not transmitted. But

data being transmitted by then complete transmission. These procedures are performed

irrespective of FIFO modes. While Auto-CTS is enabled, you can verify the input value of

CTS# by FSR[1]. If 0b, CTS# is 0b and it means external UART can accept new data, If

1b, CTS# is 1b and it means external UART can not accept more data and data in TX

FIFO are not being transmitted. If IER[7] is set to 1b, interrupt is generated by Auto-CTS

when the input of CTS# is changed from 0b to 1b, and it is shown on ISR[5:0]. Interrupts

generated by Auto-CTS are removed if MSR is read.