...the world's most energy friendly microcontrollers
2016-04-28 - Giant Gecko Family - d0053_Rev1.20
182
www.silabs.com
Table 14.1. EBI Intrapage hit condition for read on address Addr (non-mentioned Addr bits are
unchanged)
PAGELEN, INCHIT
8-bit External Device
16-bit External Device
PAGELEN=MEMBER4, INCHIT=0
Addr[1:0] changed
Addr[2:0] changed
PAGELEN=MEMBER8, INCHIT=0
Addr[2:0] changed
Addr[3:0] changed
PAGELEN=MEMBER16, INCHIT=0
Addr[3:0] changed
Addr[4:0] changed
PAGELEN=MEMBER32, INCHIT=0
Addr[4:0] changed
Addr[5:0] changed
PAGELEN=MEMBER4, INCHIT=1
Addr[1:0] incremented by 1
Addr[2:0] incremented by 2
PAGELEN=MEMBER8, INCHIT=1
Addr[2:0] incremented by 1
Addr[3:0] incremented by 2
PAGELEN=MEMBER16, INCHIT=1
Addr[3:0] incremented by 1
Addr[4:0] incremented by 2
PAGELEN=MEMBER32, INCHIT=1
Addr[4:0] incremented by 1
Addr[5:0] incremented by 2
The initial page mode transaction uses the read setup and read strobe timing as shown in Figure 14.2 (p.
178) , Figure 14.5 (p. 179) , Figure 14.7 (p. 180) or Figure 14.9 (p. 181) depending on the
used addressing mode. Subsequent transactions are started by changing the low-order address bits
and use the page access time defined in the RDPA bitfield of the EBI_PAGECTRL register. The read
hold state RDHOLD is only performed at the end of a page mode read sequence or when bus turn-
around occurs. Note that bus turn-around can occur even if only read transactions are performed as
the D16A16ALE addressing mode will drive the EBI_AD lines when programming the external address
latch. In this case one bus turn-around RDHOLDX cycle is automatically inserted in between the read
and the write action on the EBI_AD lines. Note that for the D16A16ALE addressing mode the RDPA
state immediately follows the ADDRSETUP state, so the HALFALE feature will typically be required to
satisfy the external address latch hold requirement. In the D8A24ALE addressing mode there is no need
to reprogram the external address latch for intrapage addresses as the external latch then only latches
the most significant, non-changed address lines. The following figures show typical page mode read
sequences for all addressing modes.
Figure 14.11. EBI Page Mode Read Operation for D8A8 addressing mode
ADDR0
EBI_AD[15:8]
RDSETUP
(0, 1, 2, ...)
RDSTRB
(1, 2, 3, ...)
EBI_CSn
EBI_REn
RDHOLD
(0, 1, 2, ...)
Z
DATA0
EBI_AD[7:0]
DATA1
DATA2
DATA3
ADDR1
ADDR2
ADDR3
Z
Z
RDPA
(1, 2, 3, ...)
RDPA
(1, 2, 3, ...)
RDPA
(1, 2, 3, ...)
Figure 14.12. EBI Page Mode Read Operation for D16A16ALE addressing mode
ADDR0
EBI_AD[15:0]
EBI_ALE
ADDRSETUP
(1, 2, 3, ...)
Z
DATA0
EBI_CSn
EBI_REn
RDSETUP
(0, 1, 2, ...)
RDSTRB
(1, 2, 3, ...)
RDHOLD
(0, 1, 2, ...)
ADDR1
Z
DATA1
RDSETUP
(0, 1, 2, ...)
RDPA
(1, 2, 3, ...)
RDHOLD
(0, 1, 2, ...)
ADDRSETUP
(1, 2, 3, ...)
Z
Summary of Contents for Giant Gecko EFM32GG
Page 842: ......