Chapter 14: UARTS WITH FIFOS
TX7901 User’s Manual (Rev. 6.30T – Nov, 2001)
14-4
SIGNAL
TYPE
DESCRIPTION
gbsgLastB
Input
The G-Bus Master asserts this signal to indicate the last transaction.
urtgAck32B
Output
G-Bus Acknowledge. UART asserts this signal to acknowledge a 32-bit width
read/write transfer.
urtgData[63:0]
Output
64-bit read data from UART to G-Bus
Serial Interface (Two sets)
BAUD
Output
Receive/Transmit clock, derived from CLK. Divided by the value in the divisor latch
DLL & DMM.
RCLK
Input
Receive Clock
RCLK_BAUD
Input
RCLK Select. When tied hHigh, RCLK is connected internally to BAUD; when tied
Low, the RCLK pin is used as the Receive clock.
SIN
Input
Serial Input. Data are clocked in using RCLK/16.
SOUT
Output
Serial Output. Data are clocked out using the output from the Baud Rate Generator,
then divided by 16.
DCD*
Input
Data Carrier Detect, MSR[7] status bit. Active Low
RI*
Input
Ring Indicator, MSR[6] status bit. Active Low
DSR*
Input
Data Set Ready, MSR[5] status bit. Active Low.
CTS*
Input
Clear To Send, MSR[4] status bit. Active Low
OUT2*
Output
General Control, MSR[3] control bit. Active Low
OUT1*
Output
General Control, MSR[2] control bit. Active Low
RTS*
Output
Request To Send, MSR[1] control bit. Active Low
DTR*
Output
Data Terminal Ready, MSR[0] control bit. Active Low
DMAC Interface
urtgRxRdyB
Output
DMA Handshake. Goes Low when RX FIFO contains data.
urtgTxRdyB
Output
DMA Handshake. Goes Low when TX FIFO is empty.
G-Bus Bridge Interface
urtgIntB
Output
Interrupt Request. Goes Low whenever one of the enabled interrupts becomes valid.
This signal goes to the interrupt controller inside the G-Bus Bridge.
Note:
Active Low external signals are indicated by a suffix of “*” (asterisk), or “B” (Capital B) for
Active Low internal TX7901 signals.
14.4 UART Device Register Description
This section describes the block of device registers that control each UART. There are two
of each of the device registers described in this section, one for each of the UARTs. Each
type of register is located at the same offset position in both UART channels’ blocks of
device registers.
14.4.1
UART Device Register Addressing
Most of the UART device registers are directly addressed through the address lines. One of
the following four register types is accessed: the Divisor Latch Registers, the Receive Buffer
Register, the Transmit Holding Register, or the Interrupt Enable Register. The register to be
accessed is selected according to the following: the setting of bit 7 (the Divisor Latch
Address Bit, DLAB) of the respective Line Control Register, and whether one is reading from
or writing to the accessed register. (Please refer to Table 14-2 and Table 14-3).
Summary of Contents for TMPR7901
Page 1: ...TX System RISC TX79 Family TMPR7901 Symmetric 2 way superscalar 64 bit CPU ...
Page 14: ...Handling Precautions ...
Page 15: ......
Page 17: ...1 Using Toshiba Semiconductors Safely 1 2 ...
Page 41: ...4 Precautions and Usage Considerations 4 2 ...
Page 42: ...TX7901 User s Manual Rev 6 30T November 2001 DOCUMENT NUMBER M 99 00004 07 ...
Page 43: ......
Page 259: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 1 13 Removed ...
Page 260: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 2 ...