SM470R1B1M-HT Datasheet, PDF (28/67 Pages) Texas Instruments – 16/32-BIT RISC FLASH MICROCONTROLLER

SM470R1B1M-HT
SPNS155F – SEPTEMBER 2009 – REVISED AUGUST 2012
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expansion bus module (EBM)
The expansion bus module (EBM) is a standalone module used to bond out both general-purpose input/output
pins and expansion bus interface pins. This module supports the multiplexing of the GIO and the expansion bus
interface functions. The module also supports 8- and 16- bit expansion bus memory interface mappings as well
as mapping of the following expansion bus signals:
• 27-bit address bus (EBADDR[26:0] for x8, 19-bit address bus (EBADDR[18:0] for x16
• 8- or 16-bit data bus (EBDATA[7:0] or EBDATA[15:0])
• 2 write strobes (EBWR[1:0])
• 2 memory chip selects (EBCS[6:5])
• 1 output enable (EBOE)
• 1 external hold signal for interfacing to slow memories (EBHOLD)
• 1 DMA request line (EBDMAREQ[0])
Table 9 shows the multiplexing of I/O signals with the expansion bus interface signals. The mapping of these
pins varies depending on the memory mode.
Table 9. Expansion Bus Mux Mapping⁽¹⁾
GIO
GIOB[0]
GIOC[0]
GIOC[2:1]
GIOC[4:3]
GIOD[5:0]
GIOE[7:0]
GIOF[7:0]
GIOG[7:0]
GIOH[5]
I2C5SDA
I2C5SCL
I2C4SCL
I2C4SDA
GIOH[0]
x8 ⁽²⁾
EXPANSION BUS MODULE PINS
x16 ⁽²⁾
EBDMAREQ[0]
EBDMAREQ[0]
EBOE
EBOE
EBWR[1:0]
EBWR[1:0]
EBCS[6:5]
EBCS[6:5]
EBADDR[5:0]
EBADDR[5:0]
EBDATA[7:0]
EBDATA[7:0]
EBADDR[13:6]
EBDATA[15:8]
EBADDR[21:14]
EBADDR[13:6]
EBHOLD
EBHOLD
EBADDR[26]
EBADDR[18]
EBADDR[25]
EBADDR[17]
EBADDR[24]
EBADDR[16]
EBADDR[23]
EBADDR[15]
EBADDR[22]
EBADDR[14]
(1) For more detailed information, see theTMS470R1x Expansion Bus Module (EBM) Reference Guide (literature number SPNU222) and
the TMS470R1x General Purpose Input/Output Reference Guide (literature number SPNU192).
(2) X8 refers to size of memory in 8-bits; X16 refers to size of memory in 16-bits.
Table 10 lists the names of the expansion bus interface signals and their functions.
PIN
EBDMAREQ
EBOE
EBWR
EBCS
EBADDR
EBDATA
EBHOLD
Table 10. Expansion Bus Pins
DESCRIPTION
Expansion bus DMA request
Expansion bus pin enable
Expansion bus write strobe EBWR[1] controls EBDATA[15:8] and EBWR[0]
controls EBDATA[7:0]
Expansion bus chip select
Expansion bus address pins
Expansion bus data pins
Expansion bus hold: An external device may assert this signal to add wait
states to an expansion bus transaction.
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