7480 datasheet(126/337 Pages) RENESAS

126 / 337 page

7480 Group and 7481 Group User's Manual

1-109

1.14 Serial I/O

HARDWARE

(2)

Serial I/O Status Register

This register consists of the flags that indicate the serial I/O transmit/receive status.

Figure 1.14.3 shows the serial I/O status register.

Figure 1.14.3 Serial I/O Status Register

Each flag of the serial I/O status register is described below.

Transmit Buffer Empty Flag (TBE: bit 0)

This flag indicates the status of the transmit buffer register.

• When the data written to the transmit buffer register is transferred to the transmit shift register, this

flag is set to ‘1’.

• When transmit data is written to the transmit buffer register, this flag is cleared to ‘0’.

This flag is valid in both clock synchronous serial I/O and UART.

Receive Buffer Full Flag (RBF: bit 1)

This flag indicates the status of the receive buffer register.

• When receive data is stored completely in the receive shift register and transferred to the receive

buffer register, this flag is set to ‘1’.

• When the transferred data is read from the receive buffer register, this flag is cleared to ‘0’.

This flag is valid in both clock synchronous serial I/O and UART.

Transmit Shift Completion Flag (TSC: bit 2)

This flag indicates the status of the transmit shift operation.

• When the data in the transmit buffer register is transferred to the transmit shift register, and shift

operation is started by the synchronous clock (the start bit of the transmit data is transmitted), this

flag is cleared to ‘0’.

• When the shift operation is completed (the transmission of the last bit of the transmit data is

completed), this flag is set to ‘1’.

This flag is valid in both clock synchronous serial I/O and UART.

Serial I/O status register

b4 b3 b2 b1 b0

Name

Function

At reset

Serial I/O status register (SIOSTS) [Address 00E116]

Transmit buffer empty flag

(TBE)

Receive buffer full flag

(RBF)

Transmit shift completion

flag (TSC)

Overrun error flag

(OE)

Parity error flag

(PE)

Framing error flag

(FE)

Summing error flag

(SE)

0 : Buffer full

1 : Buffer empty

0 : Buffer empty

1 : Buffer full

0 : Transmit shift in progress

1 : Transmit shift completed

0 : No error

1 : Overrun error

0 : No error

1 : Parity error

0 : No error

1 : Framing error

0 : OE U PE U FE=0

1 : OE U PE U FE=1

This bit is fixed to ‘1’.

Note: b4 and b5 are valid only in UART

7480 Datasheet(PDF) 126 Page - Renesas Technology Corp

7480 Datasheet(HTML) 126 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL