Chapter 7 External Bus Controller
7-4
7.3.2 Global/Boot-up
Options
In addition to the settings made separately for each channel, the Channel Control Registers can also
use global options that make settings common to all channels.
External Bus Controller Channel 0 and 7 can be used as a Boot memory channel. Channel 0 and 7 is
set by the external pins (Boot pins) during reset.
These settings are summarized below in Table 7.3.1. (Please refer to “3.2 Boot Configuration” and
“5.2.1 Chip Configuration Register” for more information.)
Table 7.3.1 Global/Boot-up Options (1/2)
Pin Name
Set Register
Explanation
⎯
PCFG.ACKIN
Selects the operation mode of the ACK
*
/READY signal.
0 = ACK
*
/READY Dynamic mode
1 = ACK
*
/READY Static mode (Default)
⎯
CCFG.UAEHOLD
Sets the address hold time relative to the UAE signal.
0: Address changes simultaneous to deassertion of the UAE signal.
1: Address changes 1 clock cycle after deassertion of the UAE signal.
(Default)
ADDR[4:3] CCFG.SYSSP
Specifies the division ratio of the SYSCLK output relative to the internal
bus clock (GBUSCLK).
00: 1/4 speed (1/4 the GBUSCLK frequency)
01: 1/3 speed (1/3 the GBUSCLK frequency)
10: 1/2 speed (1/2 the GBUSCLK frequency)
11: Full speed (same frequency as the GBUSCLK frequency)
EBCCR0.ME
Specifies whether to enable or disable Channel 0.
0: Disable this channel as a Boot channel. (ADDR[8] = 0)
1: Enable this channel as a Boot channel. (ADDR[8] = 1)
ADDR[8:6]
EBCCR0.SP
Specifies the operation speed of Channel 0.
00: Reserved
01: 1/3 Speed mode (ADDR[8:6] = 101b)
10: 1/2 Speed mode (ADDR[8:6] = 110b)
11: Full Speed mode (ADDR[8:6] = 111b)
ADDR[11] EBCCR0.BC
When accessing Channel 0, specifies whether to use the BWE[3:0] signal
as a Byte Enable signal (BE[3:0]) or to use it as a Byte Write Enable
signal (BWE[3:0]).
0: Byte Enable mode
1: Byte Write Enable mode
ADDR[5] EBCCR0.EACK
Specifies the Channel 0 access mode.
0: Disable ACK
*
Input Mode (ADDR[5] = H)
1: Enable ACK
*
Input Mode (ADDR[5] = L)
ADDR[13:12] EBCCR0.BSZ
Specifies the memory bus width of Channel 0.
00: Reserved
01: 32-bit width
10: 16-bit width
11: 8-bit width
Summary of Contents for TMPR4925
Page 1: ...64 Bit TX System RISC TX49 Family TMPR4925 Rev 3 0 ...
Page 4: ......
Page 15: ...Handling Precautions ...
Page 16: ......
Page 18: ...1 Using Toshiba Semiconductors Safely 1 2 ...
Page 40: ...3 General Safety Precautions and Usage Considerations 3 18 ...
Page 42: ...4 Precautions and Usage Considerations 4 2 ...
Page 43: ...TMPR4925 ...
Page 44: ......
Page 54: ...Chapter 1 Features 1 8 ...
Page 58: ...Chapter 2 Block Diagram 2 4 ...
Page 88: ...Chapter 4 Address Mapping 4 12 ...
Page 226: ...Chapter 8 DMA Controller 8 58 ...
Page 260: ...Chapter 9 SDRAM Controller 9 34 ...
Page 480: ...Chapter 15 Interrupt Controller 15 32 ...
Page 554: ...Chapter 19 Real Time Clock RTC 19 8 ...
Page 555: ...Chapter 20 Removed 20 1 20 Removed ...
Page 556: ...Chapter 20 Removed 20 2 ...
Page 564: ...Chapter 21 Extended EJTAG Interface 21 8 ...
Page 580: ...Chapter 22 Electrical Characteristics 22 16 ...
Page 588: ...Chapter 24 Usage Notes 24 2 ...