cl-ps6700 Cirrus Logic, Inc., cl-ps6700 Datasheet - Page 27

• Manufacturer Part Number: cl-ps6700
• Description: Low-power Pc Card Controller For The Cl-ps7111
• Manufacturer: Cirrus Logic, Inc.

CL-PS6700
Low-Power PC Card Controller
4.4.2 DMA Control Register
4.4.3 Device Information Register
November 1997
Bit(s)
Bit(s)
15:9
6:4
7:6
4:2
1:0
8
7
3
2
1
0
5
Description
Reserved
Enable Handshake with CL-PS7111 Using PDREQ_L. If this bit is cleared, then PDREQ_L
is always deasserted. If Power Management register bit 7 is set, then this bit is a don’t care .
Card DMA Enable. Enables card DMA transfer. A DMA transfer is defined by REG_L deas-
serted and IORD_L or IOWR_L asserted. OE_L and WE_L indicate the terminal count for read
and write, respectively.
DMA Request Input Select. Selects input to be used for DMA handshake between the
CL-PS6700 and the card. Currently, there is no dedicated card pin assigned for DMA request.
000 – Disable DMA access
001 – PCTL[2]
010 – PCM_VS[2]
011 – Reserved
101 – PCM_WP input
110 – PCM_BVD2
111 – Card always requesting DMA transfer (no handshake between CL-PS6700 and card).
DMA Request Polarity Select. If this bit is set, the selected DMA request input (as described
above) is inverted to be active-low.
Transparent DMA Request. If this bit is set, then external DMA request input is passed
through to the PDREQ_L output after being synchronized to PCLK.
CPU Initiated DMA. This allows the CPU to generate a card DMA transfer. If this bit is set, a
CPU access to I/O space is converted to a DMA transfer. REG_L is kept high (deasserted),
and IORD_L or IOWR_L is used to transfer data.
CPU Initiated DMA with Terminal Count. If this bit is set, a CPU access to I/O space is con-
verted to a DMA transfer. REG_L is kept high (deasserted). The end of DMA is indicated to the
card by OE_L low (read) or WE_L low (write). IORD_L or IOWR_L are used to transfer data.
Description
Chip ID
Dual/Single Socket. Single-socket device if low.
Revision Level. This changes as new revisions become available.
Reserved
After each DMA transfer from CL-PS7111 to CL-PS6700, PDREQ_L is immediately
reasserted.
PRELIMINARY DATA BOOK v1.0
C
I R R U S
(0X0C004000
L
O G I C
(0X0C004400
C
O N F I D E N T I A L
)
)
, N D A R
E Q U I R E D
REGISTERS
Default R/W
Default R/W
000
01
00
00
–
0
0
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R
R
R
–
27